An alternative MC-2100 dashboard replacement circuit
Terry’s dual 555 circuit
As discussed in the comments of earlier MC-2100 related posts, Terry has been working in parallel to create a circuit capable of generating the variable duty cycle PWM signal that the MC-2100 requires to operate. He’s written up a very thorough summary of his design process (click for the PDF file).
Terry’s circuit uses two 555 timers (or a single 556), two potentiometers (one is a trimmer), and various capacitors and resistors. This is a great way to get the MC-2100 working without the dash panel if you don’t have a comparator on hand.
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Doug, 
Bryan are discussing. 
Doug 12:04 pm on October 31, 2015 Permalink |
Hi Terry,
Hope you see this post here
I built Schoolie’s 555 – LM393n circuit but was not able to get it to work with the MC2100
Then I built your dual 555 timer board and was able to get my MC2100 to run my motor
A couple of notes on my build using your PDF build document
The circuit would not respond until I added a .68uf cap across the Black and Red wires coming from the MC2100. See my picture
Once I added a cap across the incoming 12v voltage supply, the circuit began to send pulses to the MC2100
I only discovered this because I hooked up my multi meter to measure the 12volt supply and the circuit started working. When I removed my meter, the circuit stopped working. I unhooked my meter and touched a .68 cap across the voltage supply and the circuit starting work. I saw Schoolie had a .47 on his circuit and so it looked like a good thing to add to your circuit
The optimal resistance I found on my build for the combo of R3 + R2 was 31k
Terry, as you noted in your PDF build document, turning off the MC2100 and then turning it back on resulted in the circuit no long working. I added a momentary switch between R5 pot and the 12 volt power supply
Tapping the momentary switch and breaking the voltage to R5 and then releasing the momentary switch works like a charm.
After breaking and restoring the 12 volt supply to R5 pot, the circuit starts up and pulses the MC2100
I am open to any modifications that may be needed on my build
Does the circuit need a filter on the blue wire to prevent the motor from messing up the pulses from the 555 board like schoolie di on hi circuit?
I was curious if you have made any changes to your original circuit since creating your PDF document?
Thanks, Doug
Here’s a pic of my breadboarded circuit using Terry’s dual 555 timer circuit
Bryan 7:53 pm on November 17, 2015 Permalink |
Minor correction to your wording – you installed the momentary switch on the R2 (not the R5) pot. Wondering if this will work on the 555/LM393 circuit…
Doug 10:33 am on November 2, 2015 Permalink |
Thanks to you Terry and Schoolie for posting this info. I would have chucked my MC-2100 in the trash and purchased a MC-60 if it were not for the info posted here and on Schoolies blog.
My finished project can be found on my web site here.
http://el34world.com/Misc/Cnc/TreadmillMotor1.htm
Doug 10:34 am on November 2, 2015 Permalink |
And here is a you tube video of my MC-2100 and your 555 timer circuit in action.
Doug 10:36 am on November 2, 2015 Permalink |
Oooops, sorry, that was the wrong video link posted above
You can delete that link.
This is the correct you tube video link
Bryan 12:03 am on November 25, 2015 Permalink |
Attempted to share a write-up of my resurrected treadmill, but apparently WordPress didn’t like it… to summarize, my treadmill control panel fritzed out and the dual-555 circuit saved me from having to buy a completely new treadmill (>$1000). My out-of-pocket was well below $100, so the return on that effort was very high. Thanks for sharing your know-how with us DIY kindred spirits…
Wesley 1:20 am on January 3, 2016 Permalink |
Great stuff all of you are doing here. I’ll admit right up front that I don’t have near the knowledge you guys do when it comes to these sorts of things. I’ve been trying for days now to hook this Mc-2100 Rev B up and get it running, but no luck. Not entirely knowing how the pots are hooked up might help as this is the only thing at the moment that I am pretty unsure of. Would one of you mind helping me out with this? I’m needing to get this onto a wood lathe next week so that I can turn some big posts with it. Thanks in advance for any help.
Doug 8:36 am on January 3, 2016 Permalink |
I can’t help, but I do have the information on a web page here.
http://el34world.com/Misc/Cnc/TreadmillMotor1.htm
Doug 8:46 am on January 3, 2016 Permalink |
This is the project that I used my Treadmill motor on. It’s a dual action aluminum can crusher