In my designs I also tend to use transistor drivers after CMOS circuit although the CMOS can handle the amount of current drawn by one LED (in particular if you limit the LED current to 7mA as I use to). I think it is healthier for the CMOS... _________________ Yves
Posted: Tue Feb 10, 2009 9:30 pm Post subject:
My Simple Clock Divider
Agreed on the transistor drivers for LEDs. Looking at the data sheet for a 4069, I get a typical value about 9mA when the chip is run on a +15V supply (listed as Io h on the data sheet). Most CMOS (like the 4017 chip used in so many dividers and sequencers) has a similar output drive, and so you're asking quite a bit for a chip like this to drive an LED and something like a gate input or two. It will probably work, but I wouldn't place bets on it lasting a long time. This may explain the problems seen with the Doepfer unit when it is patched to several outputs (although I have no idea how that unit's outputs are set up).
Tim (high output drive, especially on Saturdays) Servo
Joined: Feb 07, 2009 Posts: 56 Location: Göteborg, Sweden
Posted: Tue Feb 10, 2009 10:19 pm Post subject:
You can safely say I've been woted down on this one...
Though I didn't intend the inverters to drive the LED's. I said let the divider drive the LED's and then the inverters can "drive" the output. Perhaps íncrease some resistances... and you wouldn't be able to drive as many inputs with it, true enough... I haven't counted on it though.
I wouldn't drive an output and an LED from a 4k CMOS chip... but I think you can let the chip sink an LED and operate as normal, seing only one CMOS input.
The doepfer divider (180/181 my doepfer was built pre. -96)... I think there was BC547's to drive the LED's and for the outputs I don't know...
I actually studied the circuit while it was in my posession and I wrote it down somewhere...
I 've built this circuit on a stripboard. Everything is fine except for the reset input, wich have no effect. I 've tried feeding it with pulses, triggers and square waves but the count continues undisturbed...
I am 100% sure that the circuitry is the same as the schematics.
I 've changed the two 3904 involved, but nothing. The diode is working.
I am powering it with 12V. Could it be a problem on the polarizing of this part of the circuit? (not sure about how it works ).
Could be a mistake on the schematics?
Any help?
thanks,
tommi _________________ http://soundcloud.com/mister-vommi http://tideofsound.net
i could not find this version of the schematic on my machine anymore. if this one was the source for the board i made then it would be on my machines drives. so i don't know.
anyways, try the one below (not tested yet).
BTW, maybe one of the janitors could move this thread into fonik's place. that would be great.
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_________________
cheers,
matthias
____________
Big Boss at fonitronik
Tech Buddy at Random*Source
thanks fonik,
On the schematic you 've posted the input's resistor to ground (R5, 100K) is quite bigger than the one i 've used following the 'old' schematic shown on page 1 of this thread, also named R5, wich was 100R! Isn't it too near to ground? _________________ http://soundcloud.com/mister-vommi http://tideofsound.net
Joined: Mar 28, 2006 Posts: 1452 Location: Kansas City, Mo USA
Audio files: 45
Posted: Mon Sep 20, 2010 10:09 am Post subject:
yusynth wrote:
In my designs I also tend to use transistor drivers after CMOS circuit although the CMOS can handle the amount of current drawn by one LED (in particular if you limit the LED current to 7mA as I use to). I think it is healthier for the CMOS...
I've etched a number of Yves' Logic boards -- they make great gate drivers because they have a high input impedance (1 and 1.2 meg resistors!) and deliver plenty of current to the load. The circuit is configured as two ANDs, an OR, and a not. The circuits are easily modded -- in fact, my latest board is configured as simply four drivers.
One of the features of the board is that the LED is connected in series with the output. The LED's return feeds a 1.5K resistor that connects to ground and a 1K resistor that goes to the load. An easy mod is to replace the 1.5K resistor with a larger value -- around 10K. This causes the LED to glow dim with no load and to glow brighter as the load increases. Thus, the circuit can be used to identify the loads that pull the most current.
OK, consider this a plug for the Yusynth logic boards -- they have proven very useful in ways that go beyond the original application. _________________ -- Kevin http://kevinkissinger.com
Fonik,
I 've breadboarded the circuit you posted, and it works!
I 've used 2n3904 for the npns. I thought that maybe i could leave out the first diode (D5), since i think it's there only for protecting the jack from the pulses from the manual switch, wich i omitted on my module, isn't it?
I 've breadboarded the circuit you posted, and it works!
I 've used 2n3904 for the npns. I thought that maybe i could leave out the first diode (D5), since i think it's there only for protecting the jack from the pulses from the manual switch, wich i omitted on my module, isn't it?
yep. it is kind of an passive OR gate mixer thing.
glad it works now. have fun... _________________
cheers,
matthias
____________
Big Boss at fonitronik
Tech Buddy at Random*Source
Joined: Dec 17, 2009 Posts: 497 Location: Rosmalen, Netherlands
Posted: Mon Apr 23, 2012 3:30 am Post subject:
and rightfully so, built one a couple of weeks ago, and it works fine. Didn't make a PCB for it, just used perfboard (or at least, I designed a PCB with PC mount cliff jacks on one edge, perf in the middle and a section with a 16 pole header, resistors and smoothing caps, to allow really quick builds (apart from the drilling of all the holes )).
this is in my drawer for a while now, maybe i should offer a PCB?
anyways, i am glad you built and like it!
great idea of making your own perfboard with socket footprints and power header! _________________
cheers,
matthias
____________
Big Boss at fonitronik
Tech Buddy at Random*Source
Joined: Dec 17, 2009 Posts: 497 Location: Rosmalen, Netherlands
Posted: Wed Apr 25, 2012 1:25 am Post subject:
Nice one Matthias!
Maybe I should have done a PCB as well, it's a lot smaller than the thing I'm using now. But yeah, projects with PC-mount jacks or pots get done very quickly, but projects where I have to mount the PCB somehow stay in the drawer a longgggg time. Hate doing wiring and sheetmetal work to mount something (despite being a mechanical engineer ).
The disadvantage of the thing I did was that I didn't use Eagle but illustration software, so I don't have gerbers, so I can only make it using PnP and hence have to drill a ton of holes.
Do you have a library with a footprint for those cliff sockets?
i just finished a preamp to use my guitar with my synth gear, and fed the signal into one of fonik's dividers (i made my own) I made a video where the guitar signal is /2 and the original signal is fed into the hard sync of a x-4046 VCO.
_________________ http://www.youtube.com/user/borisandfef
I just wanted to express my gratitude for the awesome, elegant simplicity of Fonik's divider. I built two strip-board-based dividers in a day or so without a hitch. Musically , the dividers make a big difference with all four of my sequencers.
no. i did no single sided PCB for self etching for years now. the chemicals have been no problem, but i was tired of drilling the PCBs... _________________
cheers,
matthias
____________
Big Boss at fonitronik
Tech Buddy at Random*Source
yes !
i would buy a few.
An SMT version even better, but perhaps others would prefer thru hole ? _________________ In an infinite universe one might very well
ask where the hell am I
oh yeah thats right the land of OZ
as good an answer as any
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