1. Arduino Controlled DC Load
Nathan Bowers
February - March 2016

2. 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.

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

4. 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

5. Hardware
Arduino Uno
Custom DC Load PCB

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

7. 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

12. BOM

15. 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

16. https://youtu.be/P4Gjg9ADPRg