I am using a 12 V power supply to run a series of motors in Parallel expecting them to pull up to 25 ampere.
The motors are running too fast at 12 V so we need to drop it down to 9 or 10 V, preferably making it adjustable..
I am familiar with voltage dividers and voltage reg. chips, and zener diodes but never worked at such high Ampere situations, we are even looking at lamp dimmers(?)
Can anyone suggest the most efficient and simple means of achieving this without excessive cost?
The system does not need of dynamic control, I'm fishing for a hi amp voltage-regulator/ zener-diode type solution, if it exists!
Best Answer
25 Amps is a very large current, I don't believe there is a part capable of handling such current for hobbyist applications. However, you could regulate each 2 Amp branch to step down your voltage.
I found a neat LDO that will drop your voltage down to 9V and can handle up to 2 amps:
DigiKey: PQ09RD21
It is also wired in the familiar fashion for LDOs (Extracted from the datasheet):
These guys are only a dollar each, buy seven for each motor and wire them in series with each DC motor in the manner shown above.
In regards to your adjustable request: from my experience with LDOs, a resistor may be placed between pin 2 and GND, and another resistor between pin 2 and pin 3. The resistance values will adjust the voltage. Use a potentiometer to adjust the resistance. I'm just throwing out ideas.
I also like pjc50's suggestion on the motor controllers; another neat thing to look into. Best of luck!