Arduino Controlled DC Load Nathan Bowers February - March 2016

Problem I want to be able to test each power supply for the AEA’s new RPQ+ power supply before it goes into the chassis. This will speed up building the preamp because we will know if the supply is working to specification or not. This test may be done at the Contract Manufacture so it needs to be easy and quick so that we don’t have to pay a lot for testing time.

Budget <$300 Budget spent $50 for components $50 for PCB Still need to purchase Arduino Uno

System Requirements Inputs: Analog: Read bipolar supply voltage Read current Read 12V Supply Read 48V Supply Digital: Go Push Button Outputs: LCD 2 PWM for DC Load drive

Hardware Arduino Uno Custom DC Load PCB

I/O Requirements A0 +18V D6 PWM Out A1 -18V D9 PWM Out A2 V+ Current Data Buss for LCD

Power Requirements This is going to be powered off the 12V rail of the power supply so it will boot automatically when the power supply is turned on

BOM

Hardware is Hard Problems that arose Power supply rails were backwards LCD PCB layout not correct When powered off 12v current draw was excessive Ordered wrong parts Schematic was wrong for inverting OpAmp Scaling PWM voltage gain

https://youtu.be/P4Gjg9ADPRg