question about velleman sequencer hack

[moonagedaydream]

Hello! a few weeks ago, I put together one of the velleman running light kits, and turned it into a sequencer. Works pretty great, and it's nice to have another sequencer around, but i've finally ran into a wall. It doesn't have a clock in, so i've just been using it as my "master" i guess you could say. It hasn't been a problem until today, when i was trying to patch up something a little more complicated. I was wondering if anyone else has made one of these, and how i could possibly add a clock in.

If this doesn't belong in the circuit bending section let me know. seemed to fit.



MJ is unrelated. Just thought it was cool.

[artifus]

if it uses the 4017 ic the clock in is pin 14

[moonagedaydream]

It uses a 4015. and sorry, i'm rather new to this.
I pulled up a pinout for the 4015, and pin 1 says Clock B, 9 says Clock A. so would it be as simple as putting a jack in between these two pins?

Also, i would be connecting it to my modular synth. it's eurorack which i understand correctly, can put out up to 9 volts. would there have to be anything added to reduce the amount of power going into it?

[artifus]

i found this: http://www.velleman.eu/downloads/0/minikits/manuals/manual_mk107.pdf

the 555 is the on board clock outputting pulses on pin 3 which is connected to pins 1 and 9 of the 4015. so you'll need to cut the trace from the 555s pin 3 and connect that to a switchable clock input jack so that the 555 is disconnected from the 4015 when a jack is inserted and receives the external clock instead. if the 555 is socketed you could remove it and insert a wire from your external clock into pin 3 of the socket to test it. it should be fine on 9v. if it works rather than cutting tracks on the pcb maybe simply bend pin 3 of the 555 up and connect it to your jack with a wire running from the jack to pin 3 of the 555s socket which is connected to the clock in of the 4015. hope that makes sense - need more coffee!

[moonagedaydream]

makes perfect sense. Thank you for your help, i'll go give it a shot.