So I am using the Industrial High-Power Relay Controller 8-Channel + 8-Channel ADC. I have 10K resistor connected to the 5V from the relay connected in series with an NTC thermstor (10k) to AD1 and to ground. Using the votlage divider I find Vout. Using the relay I get Vout = 3.48v. But when I remove my voltage divider circuit from the relay and i connect it to a 5v power supply Vout = 2.674. Why are the Vout different when both supply 5V. Is there something in the relay that I didnt’t take into account? Is there something wrong with my relay?
The ADCs on our relay controller are already pulled high or low with a jumper on the board, this will skew your readings when working with a voltage divider circuit. Please plan for this when calculating your divider values.
Where on the board are the jumpers to pull high or low ? Thank you
Hi @bigal92
The controller you have actually does not have a pull up/dwn jumper so the ADC inputs on that board float(they are not pulled either direction). They should not be skewed in any way.