KFLOP power up problems

[hatcat]

Hi Tom,

I purchased a KFLOP & Kanalog about 12mths ago and am only now getting to connect them to my CNC lathe.

The problem I'm having at the moment is that the KFLOP (which is mounted on Kanalog) powers up and connects to the PC successfully (KMotion says connected) via USB (J3 on), but it does absolutely nothing when I connect 5V through the Molex power connector (J3 off and USB disconnected).

As I read what I can find about the issue, it seems that KFLOP should wake up and at least flash its LEDS when power is connected, but it doesn't. I am using an analog 5V power supply (so there's no 12V as with a PC supply) and it is definitely supplying 5V into the KFLOP (JP4 pin 1 to 9 reads 5V). Plugging USB in (or out) does nothing and KMotion stays disconnected.

What am I missing here please?

Thanks very much & have a great day!

Peter

[TomKerekes]

Hi hatcat,

That is strange. Your statements all seem correct to me. The only thing I can think of is some issue with the supply. Maybe noise or extremely slow ramp up? What kind of supply is it? What are its specifications? Is Kanalog connected?

[hatcat]

Hi Tom,

It's just an old school dedicated 5V supply I had laying around - transformer, bridge, caps, 7805 regulator. So 1A I'd say.
Kanalog is connected, but there's not much connected to it. Clearly USB is enough to power it at the moment.
PS ramps up within one mains half cycle.

Anyway, you've lived up to your legendary status again and got it in one!

I dragged out my old oscilloscope and sure enough there was mains ripple on the output. I stuck a cap across it and reducing 330mV ripple to around 200mV made KFLOP happy and it lit up one of its LEDs. Thank you very much!

Now to address the situation properly! I guess that the caps in the PS have dried out (at least for a start).

Thanks again and have a great day!

Until my next problem,

Peter

[TomKerekes]

Hi Peter,

Thanks for taking the time to post back.

Good luck.