A modification I might regret.

[mpboost]

I bought a Forge Motorsport BOV and installed it today. Works fine.

I thought I would like having an aftermarket BOV, but man is this thing annoying. It vents so often, and sometimes it will vent under vacuum changes. It has already started to get on my nerves and I have had it on the car less than 24hrs.

I imagine the Mopar BOV is probably just as annoying considering it is the same spot.

I am seriously debating taking it off soon and putting the stock recirculation valve back in. Anyone have one of these Forge valves and found a way to remedy the constant venting? I am thinking about shimming the spring or getting a higher rate spring in there. Any suggestions?

[GLHNSLHT2]

the problem isn't the BOV it's the tiny turbo. It spools so quick there is constantly a charge in the pipes even when your intake see's vacuum. The solution is to get a bigger turbo :)

[Garret]

lol, I can't believe you don't like the BOV noises. Those are my bread and butter for driving my car or my van

[shadow88]

The mopar one is exactly the same. you could order a block off plate from MP and use an aftermarket BOV with the tension set higher.

[GLHNSLHT2]

garrett, drive an SRT for a while. I could see how it's annoying after a while. They'll blow if you just tickle the throttle.

[Garret]

I drove the van for a week with a mitsu and an RFL for a while. I loved it... but I love the sound of a BOV sometimes I go for a drive just to make turbo sounds LOL

[Mario]

There are some bov's that do open under the slightest pressure and have an annoying sound at low boost. I can understand where you're coming from.

[Austrian Dodge]

i understand him...
more than a year ago, with the 2.5 mitsu turboed engine in the daytona, i really hated that BOV noise, just a slight different in throttle...wooooooooosh

-> 2.2 t3/t4 haha :D

[mpboost]

garrett, drive an SRT for a while. I could see how it's annoying after a while. They'll blow if you just tickle the throttle.
That definitely has a lot to do with the problem.

However my friend has a small mitsu turbo'd Honda. His car spools up just as quick as mine, but is no where near as annoying when his blows off. His car doesn't blow off during vacuum changes, and the blowoff valve doesn't stay open nearly as long when it does blow off.

During normal driving, the Forge BOV on my car seems to stay open for a long time each time it blows off.

[TurboGLH]

That definitely has a lot to do with the problem.

However my friend has a small mitsu turbo'd Honda. His car spools up just as quick as mine, but is no where near as annoying when his blows off. His car doesn't blow off during vacuum changes, and the blowoff valve doesn't stay open nearly as long when it does blow off.

During normal driving, the Forge BOV on my car seems to stay open for a long time each time it blows off.

I think its a combination of the location of the bov, the small turbo and the computer control. With the small turbo, even with a little gas it's already started to spool up and build pressure, even if it isn't enough to produce measureable boost in the intake. It get's less annoying after a while and you'll stop noticing it.

[CSX321]

I think its a combination of the location of the bov, the small turbo and the computer control.
Yes, and you have to remember that it's a surge-control valve, not simply a blow-off valve. The computer uses it to try to prevent and control compressor surge, not just to vent pressure when the throttle plate closes.

[contraption22]

I have the Mopar Blue Plate Special. It's annoying.

Anyway.. how did you hook up your Forge WGA? I have had no success at all with aftermarket WGA's.

[mpboost]

I think its a combination of the location of the bov, the small turbo and the computer control. With the small turbo, even with a little gas it's already started to spool up and build pressure, even if it isn't enough to produce measureable boost in the intake. It get's less annoying after a while and you'll stop noticing it.
Maybe I will learn to like it over time, but it just sounds so weird right now.


I have the Mopar Blue Plate Special. It's annoying.

Anyway.. how did you hook up your Forge WGA? I have had no success at all with aftermarket WGA's.
I opted not to use a aftermarket WGA. I hear a lot of guys saying that stage 1 and aftermarket WGA is the way to go. However I also hear the same guys complaining about part throttle boost problems and leaning out. Personally I prefer to keep my driveability. :nod:

[TurboGLH]

Maybe I will learn to like it over time, but it just sounds so weird right now.


I opted not to use a aftermarket WGA. I hear a lot of guys saying that stage 1 and aftermarket WGA is the way to go. However I also hear the same guys complaining about part throttle boost problems and leaning out. Personally I prefer to keep my driveability. :nod:

Maybe not like it, but not mind it as much. I don't like the blue plate all that much, but it's stopped bothering me so I left it on.

I've probably said this a thousand times over at TD, but I bring it up because it made such a difference with drivability. I'm running a modded T2 wga on the car now and with just a boost controller it had awful drivability, part throttle boost like crazy and was just no fun if you weren't at WOT. I put together a system that lets the computer controll boost up till 11lbs then switches to the BC set at 18-19. If I were to do it over I would use a TPS tap instead to only switch at WOT, but it works in the current setup just fine as the computer limits 1st gear boost and part throttle boost to under 11lbs.

[mpboost]

Chris,

Is there a writeup of this controller you made? It sounds interesting.

[TurboGLH]

There is, but I'm having trouble tracking it down. So I put together a quick drawing. (no making fun of my mad skillz in paint)

You set the switch point on the hobbs switch to whatever psi you want the grainger to take over, In my case I used 11psi (approx). I used a vacuum manifold to feed the grainger and the hobbs switch as tapping into the green line before the stock solenoid gave me erratic control, the boost would shoot to 20 drop to 10 and repeat.

You could just feed the grainger from the intake and use a TPS tap to control the the second solenoid. If I were to do it again I would probably do it that way as it's possible if you load the car up while in 4th or 5th gear to shoot past the 11psi mark while at part throttle and have it switch. But 95% of the time it behaves just like it should until you step on it.

http://i2.photobucket.com/albums/y17/TurboGLH/boostcontrollersrt4.jpg

[mpboost]

Awesome picture Chris!!!! Really I meant it :thumb:

The TPS switching system sounds more complicated, but more refined too. I was thinking you would need some sort of adjustable voltage controlled switch to do this. Or maybe an adjustable zener diode. Some way to signal your second vacuum solenoid when your TPS voltage is correct for WOT.

Any ideas?

[TurboGLH]

Awesome picture Chris!!!! Really I meant it :thumb:

The TPS switching system sounds more complicated, but more refined too. I was thinking you would need some sort of adjustable voltage controlled switch to do this. Or maybe an adjustable zener diode. Some way to signal your second vacuum solenoid when your TPS voltage is correct for WOT.

Any ideas?

They make TPS taps for triggering nitrous systems, they're also adjustable as not every car will show a full 5.0v at wot. I would pick up one of those to use.

[mpboost]

They make TPS taps for triggering nitrous systems, they're also adjustable as not every car will show a full 5.0v at wot. I would pick up one of those to use.
Yup I noticed that too while searching :nod:

I thought maybe there was a more "grassroot" style way of doing it.....aka cheap (this is how you know I am a genuine turbo dodge guy) :p

I'll have to consult one of the electrical engineers when I get to work tomorrow. See if he can come up with a schematic off hand to accomplish the task.

[Aries_Turbo]

op amp used as a comparator.... one terminal of the op amp has a ref voltage, other terminal to the tps. hit the ref voltage with the tps and the op amp chages state. little transistor to switch the solenoid and youre all set. thats the theory as i remember it. ill have to look up a circuit.

EDIT i dreamed up a little something.... Didnt try it so I dont know if its correct. maurice, if you can have it looked at, lemme know if someone who has designed circuits recently knows if it will work. the thing im unsure of is the 47ohm resistor... the 47 ohm resistor might cause the solenoid not to function. if so I need to find another transistor that the 2n3904 will switch that will handle the 400ma that the solenoid pulls. I think the coils on those things are 30ohms. EDIT

Brian

[Keito]

I have the MP BOV and didn't like it blowing off all the time.
I ordered an upgraded surge valve spring from PT Performance.
It replaces the spring under the diaphram.
The claim is it doesen't blow off as much, and it's a different sound,
short, not the long woosh.
The bad is it causes more compressor surge.
Like all the mods I've done in the last 2 months, I haven't been able to try it
out. My car is still on blocks for the winter.

Keith

[Raymont]

I bought a Forge Motorsport BOV and installed it today. Works fine.

I thought I would like having an aftermarket BOV, but man is this thing annoying. It vents so often, and sometimes it will vent under vacuum changes. It has already started to get on my nerves and I have had it on the car less than 24hrs.

I imagine the Mopar BOV is probably just as annoying considering it is the same spot.

I am seriously debating taking it off soon and putting the stock recirculation valve back in. Anyone have one of these Forge valves and found a way to remedy the constant venting? I am thinking about shimming the spring or getting a higher rate spring in there. Any suggestions?


Get an RFL...... thoes are really neat. When you can make people jump cause your BOV is so loud, then you'll know what real fun is LOL....They work best on Vans and Omnis ;) I've had a RFL on both!! You get a TON of weird looks..

[mpboost]

op amp used as a comparator.... one terminal of the op amp has a ref voltage, other terminal to the tps. hit the ref voltage with the tps and the op amp chages state. little transistor to switch the solenoid and youre all set. thats the theory as i remember it. ill have to look up a circuit.

EDIT i dreamed up a little something.... Didnt try it so I dont know if its correct. maurice, if you can have it looked at, lemme know if someone who has designed circuits recently knows if it will work. the thing im unsure of is the 47ohm resistor... the 47 ohm resistor might cause the solenoid not to function. if so I need to find another transistor that the 2n3904 will switch that will handle the 400ma that the solenoid pulls. I think the coils on those things are 30ohms. EDIT

Brian
I'll see if I can have one of the guys look that over when I get a chance. As for the 5v reference input, could a simple 2 resistor voltage divider circuit be added to provide the 5v off a 12v source?

[mpboost]

Get an RFL...... thoes are really neat. When you can make people jump cause your BOV is so loud, then you'll know what real fun is LOL....They work best on Vans and Omnis ;) I've had a RFL on both!! You get a TON of weird looks..
Not a fan of the RFL personally.

The Forge is a direct fit and I plan to upgrade to Samco IC hoses. RFL would require hard pipes which will have more connections where there could be possible boost leaks.

[Aries_Turbo]

maurice..... the 5v source must be regulated cause alt on the car fluctuates voltage and you need to start with a regulated voltage so the voltage division for the tps trigger stays constant. the regulator is 1.59 at radio shack.

for the output i forgot that you can have the 2n3904 trigger a small relay to trigger the solenoid so that the transistor doesnt sink more than 200ma. you can also use the radio shack solid state relay. (8$ i think)

ill update the diagram.

Brian

[mpboost]

Werd up :thumb:

Excellent point on the voltage dependency on alternator speed (this is why I am a mechanical engineer and not electrical).

Thanks Brian, you are the man!

[Aries_Turbo]

ok, i updated the diagram. i still might be wrong on some things. I gotta remember my op-amp and NPN/PNP transistor rules. ill double check. still have someone look at it if you can.

Brian

[Aries_Turbo]

ok i think the curcuit is right as long as the 500ohm resistor is the correct size.

when the tps voltage is lower than the ref voltage the input to the transistor is grounded and it doesnt allow the relay coil to see current. when the tps goes above the ref voltage, the output of the opamp is high (5v i think) but i dont think it has all that much current capability hence the 500ohm resistor which might have to be increased if the relay doesnt go on. you also might need some capacitors on the relay contacts and coil to absorb spikes. I need to breadboard this circuit to test it. if i get some time, i'll do it cause this would be useful in many applications.

Brian

[Tony Hanna]

Yup I noticed that too while searching :nod:

I thought maybe there was a more "grassroot" style way of doing it.....aka cheap (this is how you know I am a genuine turbo dodge guy) :p


Maybe I'm way off base here, but why not use a full-throttle switch like you would on a nitrous setup? They can be had for around $5.00 for the microswitch type that work off of the throttle lever. I've also seen one that's made to clamp on the pedal arm, but I couldn't find one to get a price.
If you're really wanting to go grassroot, use a rear brake light switch off of an old motorcycle. They work great as a full throttle switch.
HTH,

[Aries_Turbo]

yeah that works too. :) but this works for any 0-5v signal that you want control a switch with.

Brian

[mpboost]

The nice thing about doing it electronically is that it can be hidden in a black box mounted anywhere. I was even thinking it might be nice to incorporate the solenoid into the project box.

We use a few 3 way solenoids at work that are very small. It wouldn't be hard to make the whole unit as a module in a small 1.2x2.5x.5 size plastic enclosure.

[Aries_Turbo]

btw, you can get all of these parts at or through radio shack. search for a LM324 though for the op-amp. its basically 2x LM358. same op amp... just 4 of them. still small.

for the 500ohm resistor, just use a 470ohm and a 100 ohm in series. Im gonng run to RS maybe tomorrow and snag the parts and test the circuit.

you can use a radio shack 271-342 potentiometer. its a 15 turn so youll have excellent resolution.

Brian

[Tony Hanna]

yeah that works too. :) but this works for any 0-5v signal that you want control a switch with.

Brian

I hear ya. I'm just not that good with circuitry, so the switch was the first thing that came to mind.;)
After thinking about your setup, it seems like it would be really handy for those of us running alcohol injection on the older TD's with stock cals, Especially if it could be built with several outputs that are independantly adjustable. A single 3 bar map with a setup like that could be used to do the work of a number of pressure switches. For that matter, you could even use one of the outputs in conjunction with a normally closed relay on the + wire of the coil to act as a user adjustable overboost shutdown feature.
I like it.:thumb: I'd just have to have somebody else build it for me or it would never work right.:)

[boostinhardsrt]

i know you mean, i had the mopar bov on my srt for awhile and got super annoyed quick. so, i took it off and ran the stock valve for awhile. and, eventually got hardpipe and an external bov, much better. it doesnt go off unless im in boost, but it still flutters a little when not in boost because of the tiny turbo. so if you've got the money get an external bov, cuz you'll need one when yuo go big turbo anyways :D

[Aries_Turbo]

ok im at Radio shack right now on the PC that they have setup there....

they dont have the opamp in stock at any of their stores but they can order it and have it shipped to your house. order a LM324... its 1.59$. they also dont have the 275-240 relay in stock either. its like 4.50$ or something and they can order that too. i now have all the parts but the op amp so ill be testing the ckt soon.

I agree that it would be useful and if you use all 4 op amps on the chip and add more relays and 2n3904's you can have a fully adjustable 4 ckt solenoid controller.... you can also control cold start injectors provided that I test the ckt and its all a-ok. :) gimmie a little time. ill make sure it works. I have solenoids and cold starts all over the place for testing. :)

if it all works out it should be cheaper than pressure switches. oh yeah, btw, you can get free sample map sensors from www.freescale.com. they are surface mount devices but they are free. search for "freescale" and the author "Joryn" over on TD.... he and I discussed those map sensors.

Brian

[mpboost]

Sorry for not keeping up Brian. I have been swamped at work and haven't had time to pass the circuit by a second set of eyes.

Surface mount map sensors? Sounds like something I saw someone using on a megasquirt.

[Aries_Turbo]

no prob. its the same map sensor that www.rs-autosport.com uses on its megasquirts. he has a little daughter board that the mps solders to.

the circuit shouldnt need a separate map sensor as the input impedance of op-amps are really high and wont change the voltage of the map or tps.

Brian

[TurboGLH]

----. I guess I'm gonna be switching to tps control after all. Everytime I get discouraged because most td'ers are just too damn cheap it produces something that wouldn't have come from 99% of the groups out there.

[Aries_Turbo]

hehe yup. :)

im still waiting on my op-amps..... radio shack takes 5-7 business days to have the parts at your door so itll be a bit before I get one built and in my car to test. im gonna pop it in the v6 so I can make sure that noise from the electrical system isnt going to mess it up. mouser or digikey are faster so itll be a better place to get the op-amp from but all the rest of the stuff is at RS and obtained easily. oh for the resistors... different resistors in series can be used to make different values. example: RS doesnt have a 500 ohm resistor. so I used a 470 and a 100 to make a 570 which should be close enough. we'll see.

Brian

[Aries_Turbo]

ok, i have all my parts and I breadboarded it up and it works perfectly sitting there on the couch. I used a potentiometer to simulate the tps cause the tps really is just a potentiometer. the tps signal usually will be the center wire but you should test with the key on. one wire will be +5v, the other will be 0v or gnd, the third will be variable as you move the throttle. thats the one you want to tap. I updated the circuit above and you can build it exactly as shown and it will work. all the components stay cool and all the critical currents arent exceeded. I need to hook it to the car and make sure that vehicle elec noise wont mess it up. with all the low voltage signals going through the regulator, it should be fine.

Depending on what you are driving with the 275-240 radio shack relay, (solenoid, cold start, led's, etc) you might need to drive a larger automotive relay if the current is over 1 amp.

so to figure out how much current your device will draw you use ohm's law: V=IR where V=voltage, I=Current (in amps) and R=resistance (in ohms)

so lets take a few examples of things I checked out today:

Bosch automotive relay from a cavalier: 12v coil, 72 ohms (measured by me)
so what you do is take the voltage: 14.4 (what the car makes) and divide it by the resistance of 72ohms.

14.4v = 72ohms X I ----> 14.4v / 72ohms = I = .2A which is well under the 1A that the 275-240 relay is rated at.

now a cold start injector has a 10ohm coil (all the ones I measured were around 10ohms) 12v rated so do the math and 14.4v (again the car voltage) divided by 10ohms = 1.44 amps which is a no-no for the 1A limit of the RS relay.

if you want to drive something like a cold start you can substitute a Z830-ND from www.digikey.com, in fact you can get LM324 there too. i might just change the design to use the Z830-ND and the LM324 from digikey cause you cant get them at radioshack anyway and I think digikey's shipping is faster though RS's shipping is free. depends on what what you are switching. solenoids are just fine to switch and automotive relays with 12v coils are too but cold starts need the beefier relay.

ill let you know how the circuit works when on the car. i'll hook it up to the tps and the map sensors on my v6 k car soon and drive around with the relay hooked to a led so i can see when it turns on and off. im also going to make a 4 stage one (using all parts of the LM324... you need another 2n3906, the 271-342 potentiometer, the 470 and 100 ohm resistors (youll have these cause radio shack packages have more than 4 in them) and the additional relays. you shouldnt need another 5v regulator.

if you use this for cold starts, the circuit replaces 4 hobbs switches as long as you use the relay from digikey and is much cheaper.

im going to use this to control my alky injection based off of a map sensor.

Brian

[Aries_Turbo]

oh yeah, connecting the circuit to the map sensor shouldnt mess up the map's voltage even if you have all 4 op amps hooked to it... they are very high impedance. Im going to double check this with a meter but it should be fine.

Brian

[Tony Hanna]

Brian,
Would you be interested in building one of these for me?
I'm looking for something where 3 of the outputs would be able to handle nitrous type solenoids and the 4th a shurflow pump. Preferably it would have it's own map sensor like the freescale unit along with the realys maybe all inside something like one of the Radioshack project cases.
If you'd be interested, figure out how much you'd want and send me a PM. I'll paypal you the money or send you a money order, whatever works for you.

[TurboGLH]

Way to go. Now I'm gonna have to pick up some parts and put one together. Thanks again man.

[Aries_Turbo]

no problem Chris. lemme know how it turns out. Im going to be goofing with mine for the time being to try to find bugs and make sure they are worked out.

Tony, youll have a PM in a min.

Brian

[Tony Hanna]

Tony, youll have a PM in a min.

Brian
Thanks!:thumb:

[Aries_Turbo]

ok, per tony's request for a circuit that can switch nitrous solenoids (~10A) and run a shurflow pump (~7A+) i revised the circuit and included part numbers for radio shack and some digikey parts (to save $$). i did test the MPS2222A today cause I had one and I did use it to switch a 12V automotive relay to as the circuit shows and it did work perfectly pinouts are the same as the 2n3904. :) the parts list has everything in it to make a 4-stage box with all the relays inside the box, have everything soldered to a breadboard and a nice terminal strip for connections from the relays to the car and for 12v to the car and ground to the car. when i finish mine, I'll take some pics of it in a box with the potentiometers all on one side so a small screwdriver can turn them from outside the box.

have fun.

Brian

[mpboost]

Brian, awesome job as usual!

I am going to pay a visit to UF in a couple of weeks. I will see if I can get one of the electrical engineers there to layout a board in P-cad, or possibly see if I can have a one layer board routed.

I'll send you an e-mail soon. I think this circuit maybe a very useful device :thumb:

[TurboGLH]

Brian, awesome job as usual!

I am going to pay a visit to UF in a couple of weeks. I will see if I can get one of the electrical engineers there to layout a board in P-cad, or possibly see if I can have a one layer board routed.

I'll send you an e-mail soon. I think this circuit maybe a very useful device :thumb:

If you do that, drop me a pm with a price. I'd rather just stick a bunch of sm pieces onto a pcb then have to cobble something together.

[Aries_Turbo]

yeah maurice, a board would be nice... would you do a SM or a thru hole board?

Brian

[mpboost]

Actually I was thinking mostly through hole, using the components you already spec'd.

I actually found a free board software called pcb123 and started to lay the board out myself. Only problem with pcb123 is you have to buy the board through a particular company when you are done with the design. The board unit price isn't too bad as long as I buy a lot of them.

I actually talked to some of my co-workers about this. If need be, one of them has a registered copy of P-cad at home, and said he would do the Gerber files and drawings for me. That way I can use any board house I want.

At the moment I have a .063" board, 2 layered, solder masked and silk screened. Haven't finished laying it out, but it is not a terribly tough board either. I'll try and finish the layout this weekend, however I need to start buying some of the components so I can make sure I am using the right footprint from the library. For some reason I cannot find the proper part numbers for the op-amp footprint in my component library, so I am using a generic 14pin IC footprint.

Anyways, I will see how far I get on this. By the way, the board I am working with is setup to use two of the op-amps (so it can trigger two separate relays), and does not include the relays on the board.

-Maurice

[Aries_Turbo]

maurice, can you pop out another version based on the high current circuit that uses all the circuits?

if not i might look into designing one of those boards and using all the circuits... or i'll be lazy and just use a RS proto board. :)

Brian

[mpboost]

Brian,

I can try, but it is Super Bowl weekend, so it might take me a little bit to finish :nod:

What relays are you using? I wonder if there are some sockets that can be used.

[Aries_Turbo]

the relays are the ones that i listed in the last image that i posted. id go with the digikey ones. i think they do have a socket.

right now for testing, i had some factory relays for a cavalier lol.

yeah for the superbowl im taking my projector to my buddies house that has digital cable. :)

Brian

[mpboost]

I'm resurrecting this thread because I finally built a proto board that works per Brian's schematic!

Here is a pic of the proto board setup. I'm just using 8 AA's for right now since I don't have a fancy power supply to test it.
http://plaza.ufl.edu/mpbiv/pics/DSCN1277.jpg

I'm using the black micro POT to simulate the TPS signal, the blue one (which has very fine adjustment) is used to set the TPS switch point. There is an extra relay, two resistors, and transistor which I am not using shown on the board. The IC is also a LM324 like Brian spec'ed which has three other op amps built in that I am not using.
http://plaza.ufl.edu/mpbiv/pics/DSCN1279.jpg

Here is the solenoid I am triggering with this circuit.
http://plaza.ufl.edu/mpbiv/pics/DSCN1278.jpg

My next goal is to try and build a PWM circuit to drive the solenoid like a electronic boost controller does.

[Aries_Turbo]

good deal dude. lemme know how it works on the car. :)

yeah I dont have much PWM experience... but I might dabble with it in the future for fun. :)

Brian

[mpboost]

I found some interesting home-brew PWM controller schematics online.

One of which uses a 555 timer, and the other uses the same LM324 op-amp, but it uses all 4 of the op-amp circuits on the IC to work. I believe both were designed as fan controllers for custom PC setups.

http://www.nomad.ee/micros/pwm555.html

and

http://www.cpemma.co.uk/pwm.html

Take a look and let me know if you have any comments.

PS-maybe this should be a new thread in a different section?

[ShadowFromHell]

Pic doesnt work

---------- Post added at 06:18 PM ---------- Previous post was at 06:18 PM ----------

Well... now they are

[Reaper1]

Time for a holy thread revival! Brian, how did your controller work on the car? Did any electrical noise muck it up?

I REALLY want to build the solid state electronic WOT switch as I want my 2-stage boost control back! I miss it!

[Aries_Turbo]

i never really used it long term. when i had it on the car, it worked just fine.

honestly, i got sidetracked by cal stuff and i use the 2 stage (part throttle and WOT) boost control in the cal.

it should work just fine though.

you could always power the 5v stuff with the 5v supply from the ecu and tap the map/tps sensors at the ecu. that should all be pretty clean wiring if you are worried about noise.

brian

[Reaper1]

Pretty much exactly what I was going to do. I want to keep this control seperate out of the cal because I want to be able to disable it whenever I want and such, as well as my not being able to do my own cals right now. I suppose having a flip-chip would work in the same respect, but that's out of my abilities right now as well.

So, instead of having the 5V regulator I could just tap the 5V supply from the SMEC, correct? That's the way I was going to do it anyway. To my knowledge I think just the opamp might even be able to directly power my solenoid without the use of the extra relay in your design as well. Although I don't know how much amperage the opamp you speced can hold. I do know that the solenoid I'm sunning doesn't require much power at all.

Wait, maybe I'm having a brain fart. Maybe I need to run it through a transistor to run the solenoid directly from the controller. Darn it...gotta bust out the EE2 book! LOL

[Aries_Turbo]

no you cant fire a relay/solenoid directly from the op amp. most of them arent powerful enough.

yeah all the op amp stuff can be driven from the 5v supply from the SMEC.

I show a 5v regulator but you dont need it if you drive it from the SMEC.

brian