Archive of the former Yahoo!Groups mailing list: Homebrew PCBs

Hi,

Glad you liked the board. My approach to the power needed was to use a 12V wall wart with a 7805 to produce the low voltages, and just to rectify and filter the incoming line to get ~165 V for the motor. I have never seen a PC PSU that produced 170V. What was that voltage used for? If the 170V is isolated from the mains, it would add an element of safety to the project, and that would be a good thing. Without isolation, the wiring inside the laminator would have to carefully isolated from the rest of the AC wiring. Even with an isolated supply, I would do that, just as a way to reduce the possibility of accident.

It sounds to me that you already have other plans for this board:-)
 
I didn't mention this earlier, but the 8010 chip can also be controlled through software for more exotic applications. The only thing that doesn't seem to be controllable is the continuously variable frequency. The chip has an RS232 port, but that port is not available on the board without modification.  As I looked again at the datasheet, it dawned on me that this board was originally designed for solar inverters. The fact that the frequency can be varied is a bonus from heaven.

Thanks for the links, I will check them out.

One correction: your reference to 170VDC RMS should be 170 VDC Peak.

Harvey

 

Hi guys:
Thx for the link to that SPWM controller board Harvey. I have ordered the board and the FETs. I will do a open source Hackaday project on it as a laminator speed control as I get time. It seems all I need to add would be the 170VDC to obtain the 120VAC (170VDC RMS). I plan to do that by using an old PC PSU  to supply the 170VDC (internal tap) and the 5VDC & 12VDC.

As a project I may do a dedicated PIC microcontroller speed control with everything integrated (including a voltage doubler for 220/240VAC motors) as a 'safe' kit to build to deliver the 200mA capability to handle a wide variety of small synchronous motors. Probably housed in a 4" x 2" PVC electrical can with a couple LEDs for status displays.

It seems that most AC Synch. 'spare part'  motors come in the 220V variety.

As I consult for a CNC machine shop company that makes gears, I can inquire as to making a batch of gears, standard size for laminators and such with set screws. Maybe 6061 aluminum would be durable enough, but certainly mild steel is doable. Oil impregnated bronze might be available.

These two link,below,  on youtube help demo the board and demo how a micro does the job as well..including theory, BASIC code & wiring.

Demo of the sine wave PWM inverter board
https://www.youtube.com/watch?v=gtmYnbtcPVg

Use a micro to create the sine wave PWM to drive an H bridge
How to implement an sPWM on arduino/atmel (sinusoidal PWM code and explanation)

			How to implement an sPWM on arduino/atmel (sinusoida... Code and documentation can be found here: https://github.com/Terbytes/Arduino-Atmel-sPWM Second part of this video can be found here: https://www.youtub...
View on www.youtube.com	Preview by Yahoo