The pictures of MC-64 have 5 components looks like the bjt for middle power, but I can't find the power bjt in MC-60, why?

 

The pictures of MC-64 have 5 components looks like the bjt for middle power, but I can't find the power bjt in MC-60, why?

The MC-60 is the more common of the controllers. Not too worried about any differences. The MC-60 is such a durable and flexible controller, but I'm just trying to put together a simple controller I can build myself because the MC-60s are getting harder to find. I could probably make them cheaper than buying them. Don't need all the fancy features like it. Some things like ramping I can program it from the Arduino.

 

The MC-60 is the more common of the controllers. Not too worried about any differences. The MC-60 is such a durable and flexible controller, but I'm just trying to put together a simple controller I can build myself because the MC-60s are getting harder to find. I could probably make them cheaper than buying them. Don't need all the fancy features like it. Some things like ramping I can program it from the Arduino.

Is that edited schematic you sent a possible working design for my needs?

 

Two circuit in #32, in the first circuit needs a transformer, the second one doesn't need that, and the photo Diac as MaxHeadRoom mentioned in #34 that you can use MOC316x series, and you can't add the capacitor to do the filter to became DC, otherwise the motor may damaged by the high voltage.

 

You have to decide if you want to go the SCR bridge route as in the schematic you posted in #1, or the PWM route, there is a few PWM motor drivers out there for Arduino AFAIK.
I have only used the Picmicro modules.
The PWM has a few more components and has a better/quieter control at low rpm's.
Max.

 

You have to decide if you want to go the SCR bridge route as in the schematic you posted in #1, or the PWM route, there is a few PWM motor drivers out there for Arduino AFAIK.
I have only used the Picmicro modules.
The PWM has a few more components and has a better/quieter control at low rpm's.
Max.

OK, give me a couple of days to digest what you guys are suggesting. I'm looking for simple, plus I don't necessarily need to use the Arduino, maybe just create a PWM with a 555. Any comments on that?

 

I have used a 555 to PWM a motor for test purposes, it ran reasonably well, I used it to test a drive circuit before connecting to a Pic, they suggest using a low as possible PWM freq of 4-5Khz minimum.
Max.

 

I have used a 555 to PWM a motor for test purposes, it ran reasonably well, I used it to test a drive circuit before connecting to a Pic, they suggest using a low as possible PWM freq of 4-5Khz minimum.
Max.

Not quite sure how to limit the freq.
I have seen it controlled via a 10k pot for motor speed as I would need. ??

 

http://www.discovercircuits.com/DJ-Circuits/simplepwm2.htm
Simple 555 cct.
Max.

 

http://www.discovercircuits.com/DJ-Circuits/simplepwm2.htm
Simple 555 cct.
Max.

Thanks Max.
4 Questions:
1- On the timer, pins 7 & 5 what is the DIS & CV? what does it come from?
2-The 6V with the 100uF capacitor, how does this relate to the rest of it?
3-The PWM freq capacitor, is this adequate for the low freq output you were talking about? Or is there a way to calculate the freq output by its value?
4-Am I correct in assessing that to incorporate this PMW into my schematic, I would have to feed this to the opto then the driver, then to the MOSFET to safely isolate the high voltage from the low voltage.

 

The cap is a decoupling cap across the supply.
Pin 7 & 5 NC.
The PDF in particular shows a Mosfet driving the motor direct.
You don't necessarily need to isolate it unless safety is an issue, the power commons would be connected to use it with higher motor supply without isolation.
Max.

 

The cap is a decoupling cap across the supply.
Pin 7 & 5 NC.
The PDF in particular shows a Mosfet driving the motor direct.
You don't necessarily need to isolate it unless safety is an issue, the power commons would be connected to use it with higher motor supply without isolation.
Max.

OK. That answers Questions 1 & 4. Any comments on 2 & 3?
2 things about your response concerns me. I was told the MOSFET being a high voltage switching device needs a driver because low TTL logic cannot totally switch the MOSFET gate fully and it would neither be on or off, thus the need for a driver switching at 12 volts for positive on/off. It would build up a lot of heat with not being totally on or off and destroy the MOSFET.
Also I don't know if I feel confident tying the 6 Volt common with the 120 Volt common. Isn't that a big potential difference that can cause problems?
This stuff is all so new and confusing to me.

 

2-The 6V with the 100uF capacitor, how does this relate to the rest of it?

The 100uF is for a DCV filter not for a DC pulse filter.
Rest of what?

3-The PWM freq capacitor, is this adequate for the low freq output you were talking about? Or is there a way to calculate the freq output by its value?

The calculation formula is here - NE555 Clock Generator and PWM adjustable circuit.

If you worried about the turn on voltage level then you can using a logical level mosfet, sometimes if the high voltage mosfet not easy to get a logic level then you will need a voltage level shifter, it could be using one npn and one pnp two stages to do.

 

The 100uF is for a DCV filter not for a DC pulse filter.
Rest of what?

The calculation formula is here - NE555 Clock Generator and PWM adjustable circuit.

If you worried about the turn on voltage level then you can using a logical level mosfet, sometimes if the high voltage mosfet not easy to get a logic level then you will need a voltage level shifter, it could be using one npn and one pnp two stages to do.

M

Max,
That link that you sent in #49 looks like a very simple design I 'm going to try.
Looks like the only thing I'll need to change in the design is the MOSFET i'm using and the diode to a 1N4003.
The rest looks simple and sweet.

 

This takes it a little further, check out Fig10 that you can use with a 555 input also.
http://tahmidmc.blogspot.ca/2013/01/using-high-low-side-driver-ir2110-with.html
Max.

 

This takes it a little further, check out Fig10 that you can use with a 555 input also.
http://tahmidmc.blogspot.ca/2013/01/using-high-low-side-driver-ir2110-with.html
Max.

Thanks Max,
I did learn something from that, and that is, its a good idea to use a 1K resistor between the Gate & Source on the MOSFET. This prevents the MOSFET from floating during power up.
This design by Dave Johnson seems about as simple to do as I need. I do still have some keen reservations about connecting the 120VDC negative from my bridge rectifier to the same ground as the 555. Any thoughts on that?
Also I would like to use a 10K pot instead of the 500K pot in the design. Would it be correct to put a 500K resistor where the 10K resistor is now, then use a 10K pot as the speed control?
I'm still a little confused about the Frequency. I understand the pulse width as the time duration between the high and low, but isn't the frequency just a constant 0-5 Volt square wave?

 

The PWM frequency is the fixed switching Frequency, just that the pulse width is varied controlling the mean current level.
Changing the 500k pot is going to change the circuit characteristics.
connecting the power and logic commons is done all the time, isolation is usually only necessary if safety is an issue.
Max.

 

The PWM frequency is the fixed switching Frequency, just that the pulse width is varied controlling the mean current level.
Changing the 500k pot is going to change the circuit characteristics.
connecting the power and logic commons is done all the time, isolation is usually only necessary if safety is an issue.
Max.

What would need to be changed in order to use a 10K pot.
The reason I would like to change to a 10K is, I can buy them at a very reasonable price in bulk with the knobs and everything.

 

Try it first and see what the results are.
Max.

 

Try it first and see what the results are.
Max.

You scare me.....well I'm going to order some parts and let some smoke out.
That'll take me a bout a week to get them, so I'll let you know how big the fireworks are.
It surprises me that after searching and searching the net, nobody seems to have a schematic to power a treadmill motor.
I can't be the only one to have thought of this.