MadModder
The Shop => Electronics & IC Programing => Topic started by: shipto on December 14, 2013, 06:50:24 PM
-
I am in need of a little help with a circuit to supply power to a 230vdc motor from a mini lathe (just to head of suggestions of using the origional controller its not a option as it blew through many tracks on the pcb due to a stray bit of swarf).
I am no great shakes at electronics but can follow a diagram pretty well and decided to give the circuit pictured below a try.
I have modified it slightly to suit parts I have rather than whats called for (this is mostly just slight changes in resisters and capacitors eg:22k where the 20k is needed) and even though I didnt get time to scope it tonight I think it is working well and the multimeter tells me its giving me 280vdc.
I can see 2 options now:
A) leave this circuit as is and regulate the 280vdc down to the required 230vdc
B) change the components of the circuit to get the required voltage which is what I would prefer to do but am not sure how best to achieve this, I am guessing I would need to replace D7 to give me a different reference voltage?
Any suggestions would be greatly appreciated.
-
Hi
Here is a link to an excellent unit for up to 2 hp DC motors
http://www.surpluscenter.com/Electrical/Motor-Speed-Controllers/90-180-VDC-SPEED-CONTROL-W-POT-11-2269.axd
Or browse through
http://www.kbelectronics.com/kb_manuals.html
280 volts dc on a 230 volts motor is straying into the sparks and smoke release arena
A commercial unit has provision to set speed torque and maximum current and is a much safer option.
The unit in the diagram is absolutely basic no means of tuning it to the motor.
Eric
-
Shipto,
I've sent you a private message.....
-
Shipto
What was that diagram from ?? Judging by the values of C1 - 4 ( ie. 39uF ) I doubt if it was intended to output any more than 200-odd mA ... ( 250VDC @ 200mA is typical for valve kit ??? Amp / Rx ?? )
Velo is right, forget it. It just won't work.
Dave
-
Its just a diagram I found from google when I put in "hv power regulator".
However it looks like John has a tidier solution so I am going to play with this and see what does what and if i end up blowing one of the transisters it wont be a big deal.
the capacitors I am using are bigger than 39uF and are from single phase motors.
The MJE13005 is able to handle 4 amps continuous 8 amps pulsed according to the spec sheet, which is why I thought this circuit would do my job but I am probably over simplifying things with my limited knowledge of this electronic wizardry.
-
Its just a diagram I found from google when I put in "hv power regulator".
I am going to play with this and see what does what and if i end up blowing one of the transisters it wont be a big deal with my limited knowledge of this electronic wizardry.
Rather that than injuring yourself.... :zap:
How did the existing controller die? Swarf in the box?
Is it the board with the mosfet(s) on it?
They can be troublesome....
-
Rather that than injuring yourself.... :zap:
not too much worry of that I am playing with this with 3 rcds in place (house, workshop and a plug in one) not to mention a healthy respect of the electricity :)
How did the existing controller die? Swarf in the box?
Is it the board with the mosfet(s) on it?
They can be troublesome....
I assume stray swarf was the culprit ( might not have been) the panel was out of the machine but still connected to the plastic board at the time just went pop and upon inspection I saw some of the tracks had blown around the relays.