ndzied1
Lifetime Supporting Member
I have been asked by the boss to make a test box for the service and shop guys to test proportional valves. I have to have an output for 24V to power valves with on board electronics and another output that should be switchable between a 0-10V signal and a +/-10V signal.
Will the attached circuit work? I know it will really give me 0-12V and +/- 12V but I'll have a meter on the system and didn't want ot have to deal with a separate DC supply for the +/- 10. Is my thinking right that:
Will the attached circuit work? I know it will really give me 0-12V and +/- 12V but I'll have a meter on the system and didn't want ot have to deal with a separate DC supply for the +/- 10. Is my thinking right that:
- Since the valve command signals are feed into a differential amplifier circuit that it doesn't matter that the ref. for this signal is not the 0V from the 24V supply?
- With the dividor resistors an order of magnitude less than the signal pot that they won't interfere too much with each other... (I'm not looking for anyting perfectly linear here, just something where I can increase and decrease the signal and observe what happens)? Maybe I should use a 10k pot?...
- Looks like I'll need 1/2 Watt resistors for the 320 ohm dividers. I took the current through the dividers as 24V / (640 total ohms)=37.5mA. Then I calculated the resistor power as 320 ohm X 0.0375^2=0.45 Watt. Is this right?