AC Motor Driver [150199]

This motor driver drives AC motors in leading- and trailing edge mode and in sync mode. Also usable for lights and small heaters up to 1000 W.

This motor driver drives AC motors in leading- and trailing edge mode and in sync mode. Also usable for lights and small heaters up to 1000 W. Please read the magazine article for all the details.

Want to build it? The PCBs and preprogrammed MCU are here:
Power Electronics Board, bare PCB
Control Board, bare PCB
Preprogrammed microcontroller

Discussion (9 comments)

A.J. Jeuring 5 years ago

please, where can i find the 'manual' of this forum. i am new here and i don't have any experience with this way of discussing.

0 Comment(s)

Geoffroy 5 years ago

--- SAFETY CONCERN ---
The insulation between the two secondary windings seems unknown !!! (The Myrra technical sheet specifies an insulation voltage of 4 kV only between the primary and secondary windings!)
One of the secondary windings of Tr1 is connected to the main, while the other supplies the controller circuit.
Therefore, I think that the controller circuit is insufficiently isolated from the main and must be considered as potentially dangerous.
Cordially

myrra-transformer-datasheet-20200524134310.png (29kb)

1 Attachment(s) 0 Comment(s)

Geoffroy 5 years ago

--- SECURITY CONCERN ---
The insulation between the two secondary windings is unknown !!! Myrra datasheet specifies an insulation voltage of 4 kV only between the primary and secondary windings ! (see snapshot).
One of the secondary windings of Tr1 is connected to the main while the other provides energy the controller circuit board.
Consequently, I think that the control circuit is insufficiently isolated from the mains and should be considered as potentially dangerous.
Cordially

myrra-transformer-datasheet.png (29kb)

1 Attachment(s) 0 Comment(s)

Chris007 5 years ago

Hello,
is it a good idea to detect the load typoe (inductive / capacitive) and automatically adapt the driving mode ?
Has it been expolored ?
Thanks

nar 5 years ago

where can I see the schematic diagram in pdf?

1 Comment(s)

cetoutotomatix 5 years ago

It would be very interesting to have a look on the microcontroller software. Can we get the source ? I guess it is C / C++ written ?
TC

A.J. Jeuring 5 years ago

Hello, I did build it. The tests on page 69 (dutch version):
voltage IC pin 1: 21 V (!!!) ; pin 3: 5V. seems ok
+ and - B2: 21,1V (!!!)
Who can explain 12V~ from trafo via rectifierbridge + reservoir capactitor becomes 21V=. in stead of nearly 15V=.

I started however with a normal lamp 60W.
Mode Int: flikkering effect.
Mode Lead: ok
Mode Trail: ok
again Int: flikkering and after 5 seconds .........DEAD!

What did i / can be wrong. Please help.
I show you in the screen of my simple componenttester the unsoldered Mosfet STW2626n...
???

AC 1kVA motorcontrol albert (1538kb)

ElektorLabs 5 years ago

You can download the software from the magazine article page (also see link ta the top of this article): https://www.elektormagazine.com/magazine/elektor-139/57010

2 Comment(s)

Jean-François Bernard 5 years ago

Is the limitation of 1KW caused by the pcb or is it caused by some componants ?
Is it a way to change some componants to increase the limitation to 1,5 KW ?
Thanks.
J-F

0 Comment(s)

Geoffroy 5 years ago

Hello,
In the french edition of Elektor, the Myrra transformer part number is 44327. When I search on the Myrra web site, I found a 1 x 9V 1.5VA transformer ...
What's the right part number, please ?
Regards,
Geoffroy

A.J. Jeuring 5 years ago

Het ware prettig de benodigde onderdelen als kit bij u te kunne bestellen! Wellicht over enige tijd?

ElektorLabs 5 years ago

The correct part number is 44237 (two digits swapped in the components list, it is correct in the text, page 74, 3rd column, middle). On the Myrra site it is here: http://myrra.com/encapsulated-50hz/?fwp_search_encapsulated-50hz=44237
All major distributors seem to carry it, e.g. Farnell 1214601.

2 Comment(s)

Colin Wilson 5 years ago

Good project chaps but, using a 40 Pin PIC for this? with only 7 I/O used. Really guys?
Also I was thinking I could etch the board myself after reading on Page 66, Power Electronics Board, "It's single-sided with through-hole parts only" looking at the artwork pdf's seems to me to be double-sided? or is that a typo?
Colin W