The 5V output of the Jrk does not have enough current to power my circuit. However, I’d like my circuit (which also has ADC channels and several sensors that run off 5V) to share a 5V supply with the Jrk.
Can I power the Jrk with an external 5V supply? Would it be as simple as removing the 5V regulator from the Jrk and providing power to the Jrk through the 5V pins from my own 5V source?
Hello.
Why do you want the 5V to be shared? Changing the Jrk’s 5V source isn’t that simple because there’s a circuit there to switch power between USB and the external source.
- Jan
EDITED: I must be blind. In reading over the Jrk manual it says they have transient protection up to 40V.
Hi,
I realize I should have been a bit more clear.
These are being used on an RV, and the power supply, although coming from batteries, has a lot of noise and transients when the engine is running. Also switchovers from various power (engine running, external AC or internal AC from a generator) tend to create noise/transients.
My previous experiments with PIC’s in this environment has produced strange bevahiour unless steps are taken to ensure the quality of my power.
Since I have to make a “clean” 5V supply for my own circuits, I thought it would make sense to also power the Jrk’s (I’m using 12V12’s, BTW) from my same power supply. However, if the Jrk’s already have a power supply that can handle all sorts of problems like transients then I wouldn’t need to power them from my own supply and all this is moot.
I don’t really want to make a “clean” supply to the Jrk at the high power side since I don’t care if there is noise on the motor driver side. I’m only concerned with the PIC locking up or acting strange from power supply noise. It would also increase cost & size having to filter and clean the high current supply.
This is why I thought it might be possible to “separate” the Jrk’s 5V supply from the high current supply and only filter/clean the 5V supply.
Out of curiosity, if the Jrk is connected via USB and also connected to a 12V supply, how is it powered? Which “source” does it decide to use? In my experimenting I’ve regularly connected & disconnected my 12V supply while leaving the Jrk connected to my computer and have never had any problems, so the power supply “switching” appears seamless to me. 
If the jrk is connected to USB and also connected to a VIN supply, it will be powered from the VIN supply. --David
