how do i build a voltage multiplier for changing 6 volts to 12 volts using diodes and capasitors?

hi, since my last question failed miserable resulting in me wasting a bunch of good dollars on a useless , and at the time what was described as a "voltage multiplier", uln2003an darlington transitor array which doent seem to do anything like i was told, i am going oldschool and building a voltage multiplier so i can switch a 12v relay card from here, to power 2 motors via remote control using a 9 amp 12 volt current (10 bats X 1.2v X 3A )X 3 sets in paralell , for my r/c tank which i have used a receiver from a toy car which i have increased its remote control signal to up to 100m away (its a 40mhz remote from china nothing special). anyway
i am trying to aquire a 12 volt current ( any amperage above what seems to be less that 5 ma according to the relay cards description) from my receiver that gives me 6 volts 700ma from the motor and 4 volts 900ma for the servo. recently i lost a diode for one of the 4 relay cards i am using so i sent my mother to buy me a uln2003an from jaycar and a single 1n4148 diode from jaycar as well, somehow she was tricked into buying a 100 bulk pack (wich she payed twice for despite getting only 1 bulk pack) but did get me the diode i needed for the relay to work without blowing the "on " led rendeing the relay for somereason inoperable. i have 99 1n4148 diodes now and i want to know if i can make these into a voltage multiplier for the relay to get turned on at 12 volts, using capasitors as well, i know it can be doen, i just dont know what kind of capastor to use or how to assemble it once i have the capasitor. please help em i have een stuck with this for ages and the answer is no i dont know how to use a transistor to switch the relay all i see is 4 ports 12v in 12 v out (for switching relay on) and the switcing part wich is conected to relay contacts



links to the diodes i have and the relay ard
also heres the transistor i have

despite description it says uln2003an on the chip

You're still obsessed with this as a voltage multiplication problem. Your original problem was turning on 12V relays from your 12V motor, powered by your 12V battery pack. Is that what you are

Building a voltage multiplier is not old-school, its actually very difficult, especially to derive a decent current from it.

I'm sorry you haven't understood what you want to do properly, but all you appear to want to do is switch a 12V supply, which is absolutely, trivially, simple.

Just confirm you have a 12V supply.
oldmanbeefjerky (author)  steveastrouk6 years ago
i never said i had a 12 v power supply , well at least not for the relays to be switched by anyway, what i have is a receiver which can only uotup 8 v, the receiver rceives the signal from my remote and well you know the rest, it turns on,.
and you got that wrong, im not switching on a relay from the motor at 12 v im using a 12v signal to switch on the relay to switch on the motor, problem is as i just said i dont have 12v to , only 8 v to switch the relay with, and remeber this,i the receiver is what has to turn on the relay not my 12 battery pack , which is what the motors are being powerd by.

i do confirm i have a 12v battery pack, it runs at 12v 9 amps , but i canot use this to power my receiver as it will blow up like the last receiver board i used. the receiver changes the voltage to 8 volts constant no matter what the input so long as its above 4.8v, and the amperage is changed acordingly also (divided by how many times the voltage is multiplied, losing always 100ma to power he receiver )

now just to put in it short heres my problem and heres the solution, problem is i cant reach my solution

6v battery powers receiver / remote controlls the receiver.

wehn remote turns on receiver with forawrds or backward the receiver gives out 8volts +/- (to power the small motor it was previuosly conected to)

i want this 8 volts to be turned into 12v so when i turn remote on, receiver gives 8 volts which becomes 12 volts which turns on relay which turns on circut of 12v 9 amps curent powering 12v large motor which will make my r/c tank move.

orksecurity6 years ago
You need more than diodes and capacitors. You need to convert the DC to an oscillating waveform, put that through a transformer to step it up, then rectify/filter/regulate it back to DC. See existing Instructables on that topic, or websearch "DC to DC converter" for designs.