I know we got some smart electrical guys on here. What's the best way to step battery voltage down to a constant 8 volts?
Printable View
I know we got some smart electrical guys on here. What's the best way to step battery voltage down to a constant 8 volts?
First we need to knowQuote:
Originally Posted by thedon809
1)how much current you need?
2)How clean does the power need to be? Ripple?
3)Voltage accuracy?
For example, if the current requirement is low you could use a series resistor and zener diode.
Higher requirement could utilize a voltage regulator either linear or DC-DC.
If you could say 8V +/- 0.1V at 100mA.
If you are not 100% sure of the requirements, let us know what you are going to do with the 8V.
Here are a few modules that I have used in the past. Adjustable voltage with 50mV ripple
https://www.ebay.ca/sch/i.html?_from...r&_sacat=92074
I need to step down voltage for a speed sensor. Here is basically what I'm trying to do. Early ZJ grand cherokees with the 4.0l came with the 42re but they had a standalone TCM whereas all other RE equipped vehicles had the tranny controlled from the PCM. I'm trying to see if the 42re TCM will control a 46re that's used behind a gen3 hemi. The only inputs the 42re TCM seemingly need are TPS and 2 speed sensors. The Jeep used an 8v reference for the 3 wire speed sensor. If this proves successful, it will be a gamechanger for making hemi swaps more affordable as 46re's are dime a dozen.Quote:
Originally Posted by chromguy
https://drive.google.com/uc?export=d...tJo_D3hhpzyq1j
Another diagram
https://drive.google.com/uc?export=d...cO9WetwRi5WgDJ
This is a low current application and thus I would get a good quality name brand linear regulator.
7808 style is old school and only needs 2 external cap as per the datasheet to work well.
https://www.digikey.com/product-deta...1-5-ND/4280196
or even the TO-92 package should work well for the small current you need
There are tons of options here,
Thank you sir. I will order one of those up and build a harness. I have a 96 ram 1500 so it will be the test mule. If it works, a hemi swap will be likely in it's future.
you are welcome, remember to also order a 0.33uF and 1uF cap as per datasheetQuote:
Originally Posted by thedon809
When I have done this for my cars (swapping to a newer style hall effect speed/distance sensor) I just used a 220 ohm resistor. I think that is the value. My understanding is that the 8v requirement is not very strict...