How do you control a 12v power supply with a 0-5v input signal?

I want to be able change the amount of power supplied to a device 12v device depending on a 0-5v input signal. The idea is that at ~1v the device operates at low speed and at 5v the device operates at the highest speed. The device is an electric water pump.How do you control a 12v power supply with a 0-5v input signal?
you probably don't want to futz around with the internals of the 12 volt supply, as you will need the schematic and be able to analyze it. Although that may be the best solution.



If the motor will withstand it, you can use a Pulse Width Modulator with the 0? volt signal changing the duty cycle from close to 0% to 100%. This is a bit elaborate but best for power saving and heat dissipated.



Third solution is to add a external amplifier/regulator. You need one that will operate with close to zero drop and with your 0? volt control signal.



A simple solution that may work is to first amplify with an opamp the 0? volts to 0?2.7 volts and apply that to a power transistor emitter follower between the 12 volt supply and the pump. But you will need 15 volt supplies.



.How do you control a 12v power supply with a 0-5v input signal?
You need to understand how the power supply is made to achieve this.

You have to modulate the reference in the power supply, but not all makes and models will tolerate this.

I would suggest using an amplifier like TDA2030 or LM3886



Hope this properly answers your questionHow do you control a 12v power supply with a 0-5v input signal?
There are many electronic devices that can do this.



Research voltage amplifier, voltage regulator, voltage

multiplier, variac, SCRs and thyristors like triac etc.

perhaps a simple potentiometer arrangement might do