Voltage regulator

[metiz]

I'm working on a little project that uses a 12v intank automotive fuelpump. I need to regulate fuel flow and there are 2 ways of doing this, using a bunch of fittings, ballvalves and servo's, or some sort of voltage regulator.

Current draw is between 4 and 7 amps. I need to be able to controll the voltage from >0v to 12 volt. Can anyone give some suggestions on how to do this with, preferably, a cheap off the shelf item, like a variable transformer or something?

[Johansson]

Use a cheap PWM controller, cost almost nothing on Ebay.

[Richard OConnell]

I've actually been looking for a good voltage regulator as well. One that would change 12 volt to 5 volt and be able to sustain up to 8 amps. It also needs to be as small and lightweight as possible.

[metiz]

Found this. Not sure if I understand what the ad says, but can that thing take 12v and turn it into a lower voltage?

[Johansson]

A PWM controller doesen´t regulate voltage but the lenght of the "pulses" somehow, don´t ask me how it works but you can control speed on a 12V motor with it.

[metiz]

This one looks like it should work perfectly. Richard, doesn't this fit your criteria as well? If imput is 12 volt, it can take 12.5A of current draw

[Richard OConnell]

That looks pretty cool, but it looks like it has more bells and whistles than what I need. I'm also leaning towards something a bit more robust that could take a beating. Something like this, but maybe slightly higher amperage if i can find one.
www.ebay.com/itm/A-S0-Step-Down-Voltage-Regulator-DC-12-24V-to-5V-5A-25W-Buck-Converter-Module/300949665430?_trksid=p2047675.m1850&_trkparms=aid%3D222002%26algo%3DSIC.FIT%26ao%3D1%26asc%3D11%26meid%3D896679617666544926%26pid%3D100011%26prg%3D1005%26rk%3D3%26rkt%3D5%26sd%3D321182483077%26

It needs will be supplying a spark gap ignitor. Bought 10 of em from here:
www.sparkfun.com/products/11218

EDIT:
the reason behind me needing more than the 3 amps suggested on the product page is that several people who bought these claim it is pulling a peak of ~8 amps. That could have to do with the size of the spark gap, but I prefer over-engineering to under-engineering.

[turbochris]

the first one you picked will run your fuel pump as you asked. Just keep an eye on the heat sinks, if they get too hot you may need more cooling. As anders said it's PWM, not true 0-12 volts but motors don't need that.

Richard I have a whole box of regulators. Courtesy of Texas Instruments Sample program. Free electronic stuff is way cool!

[metiz]

Hey Chris,

Yeah that one would be ideal but I live in the Netherlands so shipping would be like 40 dollars. The more expensive one a couple posts above would do the trick too right? that one's in the UK and shipping only cost a few dollars.

[Deleted]

Aug 28, 2013 17:51:02 GMT -5 Richard OConnell said:

That looks pretty cool, but it looks like it has more bells and whistles than what I need. I'm also leaning towards something a bit more robust that could take a beating. Something like this, but maybe slightly higher amperage if i can find one.
www.ebay.com/itm/A-S0-Step-Down-Voltage-Regulator-DC-12-24V-to-5V-5A-25W-Buck-Converter-Module/300949665430?_trksid=p2047675.m1850&_trkparms=aid%3D222002%26algo%3DSIC.FIT%26ao%3D1%26asc%3D11%26meid%3D896679617666544926%26pid%3D100011%26prg%3D1005%26rk%3D3%26rkt%3D5%26sd%3D321182483077%26

It needs will be supplying a spark gap ignitor. Bought 10 of em from here:
www.sparkfun.com/products/11218

EDIT:
the reason behind me needing more than the 3 amps suggested on the product page is that several people who bought these claim it is pulling a peak of ~8 amps. That could have to do with the size of the spark gap, but I prefer over-engineering to under-engineering.

Hi Richard they work just fine with the sparkfun kit, we been using them over here for some time, you do need to make sure you get a good 12 volts to them any thing below that from batteries dropping off then they dont work.... with a few more bits you can make them do this

youtu.be/SI22x8DMHqk

[Deleted]

Aug 29, 2013 3:14:00 GMT -5 metiz said:

Hey Chris,

Yeah that one would be ideal but I live in the Netherlands so shipping would be like 40 dollars. The more expensive one a couple posts above would do the trick too right? that one's in the UK and shipping only cost a few dollars.

Try one of these.... www.ebay.co.uk/itm/12V-30A-DC-300W-Motor-Speed-Control-PWM-HHO-RC-Controller-/130923676683?pt=UK_BOI_Industrial_Automation_Control_ET&hash=item1e7ba8c40b

loads on ebay, i used one just like this on my oil pump, with thick oil on cold days it worked fine

[metiz]

Hey Andym,

I already bought the one mentioned earlier. Should arrive tuesday or something. It has a higher imput voltage range so it will still work when my battery drops below 12.

[Deleted]

Aug 31, 2013 15:31:18 GMT -5 metiz said:

Hey Andym,

I already bought the one mentioned earlier. Should arrive tuesday or something. It has a higher imput voltage range so it will still work when my battery drops below 12.

Sorry think you mistake what i was saying, the 12 volt drop off related to one i mentioned for Richard,

What pump you using, is it Bosch efi, they can draw up to 15 amp, and if you dead head one a lot more.... they are also rated to 16 volts

"It has a higher imput voltage range so it will still work when my battery drops below 12" ? confused, if it has higher input voltage then when your batteries drop below 12 volt how good will it work and how much control will you have

[metiz]

I mean it has a higher imput voltage range, meaning that if my battery drops below 12 volts, the circuit board will still work. I have a no-brand intank fuelpump. It pumps 2 liters a minute at 2 bar. I know for a fact that it will never draw more than 7 amps because that is the maximum output of my lead battery and it runs just fine of off that.

I if the battery drops below 12 volts then there's still no problem. I need about 1 liter a minute maximum