Triggering the Data input of a CD4015 from Gate sequencers

[Richarius]

Anyone out there have any solutions to this?

Running a CD4015 4 BIT Shift Register on +12V / Ground, it's Data In will not accept incoming data from, so far:

- Bastl Knit Rider step output, as a Trigger or a Gate. (+5V)
- Ladik S-180 Gate Sequencer. (I DOES with my Euro to Lunetta level converter. The above Bastl, does not, either.)
- Delptronics Trigger Man - only, with it sent through a 4ms RCD in Gate mode. 1ms or 10ms outputs from the Delp., made no difference.

Now - I'm going to go and look at the Datasheet for the 4015 to see if I can make out what the Clock / Data inputs are expecting Voltage wise at what length of time.
So far for me though, it's quite the set of puzzles to figure this one out. :-/

Any help appreciated.
Ryk

[Richarius]

The 4015 is expecting incoming data to be at least 0.7 x Vsupply. The Bastl Knit Rider is only spitting out +5V. Solution? Amplify it.

[PHOBoS]

That would have been my guess. Most CMOS chips like a high voltage level close to the supply voltage, the 4017 in particular
can be a little bitch about it. When using external control signal I like using a transistor + schmitt trigger combo or an opamp
configured as a comparator. The latter one is especially useful when interacting with modular synths although it could benefit
from some added hysteresis.

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[Richarius]

[dk]

I just sorted that very same problem while trying to breadboard one of your 555 AD/AR's, PHOBoS... running it at 9V seemed to give better attack and decay/release times, but I was trying to trigger it off 5V. Used the transistor circuit you posted (which I had nicked off your lunetta keyboard thread) and it worked like a charm!

Incidentally, do you find with those envelope circuits that the attack knob has an impact on the overall output? (sorry in advance for getting off topic! )

[PHOBoS]

[dk]

Cool, will do!