DIY Intrument panel voltage regulator mod

Quiescent current draw is 5 ma. 5ma x 5v = .025 watts... I was wrong with .01 watts, my mistake. Though I am not sure exactly but there may be some special 7805 ICs that may be even lower, but at lower power rating.

I can and will post my current draw on my modded regulator without load and with a 25 ~ 35 ohm load. Should have both readings within 24 hrs.

Oh, I just realized I didnt mean to sound that I questioned the 2.5 watts during operation. I was stating that the internal operation power draw is less than the thermal oscillating switch. I think I was on the other side of the street with his subject.

Edited by 304-dude - Mar/03/2016 at 5:46pm

fed ex arrived three days from ordering so that,s great,fitted the unit to the back of the gauges and nothing happened.I can hear the unit clicking away but no needle, so Ill ask an expert so here we go

Edited by tony matthews - Mar/04/2016 at 1:47pm

Tony, do you have a good solid, clean ground connection to the body from  the battery. There should be a strap that runs from the crossmember to the body. It might be something as simple as that.

I looked at real time's site, and it seems to be a bit of fluff on what they say is best. Of coarse they are king, but I have only a gripe on how they make comparisons, being so short sided.

The only main fact worth noting is it is better than oem. As for everything else they list is overly one sided. If they would clean up and post facts over their best, fair, poor scale... then I would not place them in the relm of Ebay product hype sales, which have very little weight in my book. Their poor scale rating makes them look cheap in my opinon, as I put my test facts up for all to see. At least with my facts peeps can valadate what will fit their needs and at what cost.

I did note... not all 7805 IC regulators are built the same. I had 800ma running on a load run, mine did not activly over heat without a heat sink.

Each gauge will consume up to 220ma. But that is with a full tank with boiling hot engine and if equiped wih oil pressure gauge, hitting 70+ psi.

Under real world conditions we are looking at 400ma to 450ma max. So operating at 1/2 the rated wattage for any power condition with electronics has never failed me yet. Again, I over engineer, even with minimal design.

My instructor once said, why would you make an 8bit microcontroller testing circuit, to operatate in a radioactive environment? I said, because the components are available, and you just never know when you'll need such engineering. HA!

Yes, I am aware of an input capacitor, but for the most part, that is with the load capabilies of the source. Most electronics do not make the source stronger than what the output requires. So power sags and fluctuations from a changing load, will not effect output stability. Like you said operational load is very stable.

I recommend and gave a link to an IC that is 2.5amp rated. So even if any one should go run their engine under extrems to see how bad it will melt down, there will not be any issue with 800+ ma causing too much heat.

Thanks for your input and glad you found such simple design worth while and cost effective.