detailed circuit

Ok so I am an expert in low voltage circuits and I have created a circuit I want to run in my car, but the catch is my cars wiring that I need to hook it up to is 13.8V, 1.5mA and the circuit that I am working on I have set an operational rating at 5V and .5mA so how do I make it so I can change the single input down to those specs and then take the 3 outputs and raise them back up to the 13.8V and 1.5mA. Thanks so much for all help on this! ~KennyNovice tinkerer, master of mistakes :)

use a 5v or an adjustable voltage regulator to drop the input voltage. the output of your circuit can be used to activate 12v relays via transistors. from you description, i believe you will need nPn transistors.

Ditto! There are 7805 (5V 1A) or LM317 (variable, 1.5A) voltage regulators... Might be worth reading ANs (Application Notes) etc for extra protection if you add capacitors etc (ie, reverse polarity diodes (IN4004 etc) across output, from input to output, and as with most car circuits, across input). And a fuse (say 1A). Outputs as per 91stt - commonly called "Open Collector" outputs. When "on", the output is shorted/connect to ground. This might be through transistors, FETs, relays.... Because it is switching to ground (0V) else "Open" circuit, the "next system voltages" don't matter. (Assuming the open-collector output can handle the "off" voltage of the next "input".) Computers & logic (CPUs and interfacing) commonly use open collector outputs. Some car systems too - like horns, ignition coils (ie, both points and ignitors), wiper motors. Some use it for lighting - like old VW Beetles and Datsuns - and they often suffer lighting problems as a result.... but that's a different story! Sorry if too much detail but not enough.... I just wanted to endorse, and provide some useful hints.

Ok so I see voltage regulators sometimes need heat sinks when pulling stuff down from that high of voltage, will I need a small one for this? Also what do you mean by 91stt? Basically I need to take the power from a turn signal on my car, knock it down to run through my special circuit to create patterns on the 3 bulb output that will be run at the same power as originally sent to the one bulb. And would relays be able to stand up to the high voltage and current that I would run through it on a long term basis?Novice tinkerer, master of mistakes :)

"91stt" - the first Replier (2nd Poster) in this thread. The power dissipated by the regulator is its voltage drop x the current through it. EG - 12V to 5V, but assume max auto voltage of 16V, hence 16-5 = 11 Volts dropped - let's say a nice round 10V (ie - allows for 15V max input). 10V @ 1.5mA: P = VI = 10V x 1.5mA = 15mW 10V @ 150mA = 1,500mW = 1.5W. etc. BUT - maybe you should explain your aim (preferably) and then/else your circuit.... If you are using a flashing signal to power the regulator.... NO!! If the regulator is powered of +12V but the 5V circuit gets it signal from the flashing signal (voltage limited to 5V of course!), then that's okay. The +12V could be from the Ignition, or the flasher switch before the flasher can. (That is NOT common here except where the indicators are shared with other bulbs - in our case reverse bulbs; in USA - it's stop bulbs.)

oooooo lol I never even noticed his name lmao. Naw they are side markers, I am using power from the turn signal switch on the stalk to activate the circuit, this will then in turn power 3 flashing bulbs that will be the side marker. But I need to take the electrical charge from the signal switch and down it enough for the circuit. Then it will be boosted so that it can turn on the 3 bulbs on the side marker. I know the power drops involved, I was just saying I need to down the entire power of the circuit instead of the voltage or just the current, I was just saying that I know I could down the voltage and up the current but for this circuit it would not work because it would blow it out with high currents or high voltages. But overall your suggestion is to take a voltage regulator to drop the initial charge then use relays to bump it back up to the original charge?Novice tinkerer, master of mistakes :)

can you post up a diagram of your schematic? we could be more specific with the circuit details if we knew how it is all going to come together.

Sure I can definitely get you a small schematic of it tomorrow, I have work all morning then I have some stuff to do but I will do my best to get one up. Thanks so much for both of your help! Like I said I am good on the same power but I get lost when it comes to adjusting volts AND amps.Novice tinkerer, master of mistakes :)

It they are 12V sidemarkers, I don't understand why you need a 5V circuit - there are several ways of using 12V - some simply using ground connections or diodes. If it's some 5V logic chip use a CMOS equivalent (3-15V). Otherwise what the heck is it? But post the circuit. And find out if your indicator-switch switches 12V to either side's flasher circuit, or if it switches the flasher can (output) to either side. If it's the former, I doubt you'd need anything other than (a) relay(s) - not voltage converters.

what year and model is you car? oldspark, skier is saying that the circuit he built will only accept 5v that is why he needs to lower the voltage. probably because he used cmos components.