Emco Easycut Bandsaw not starting

[Alastair HParticipant @alastairh]

About 10 years ago I bought one of these saws. It hasn’t been used much, and I can’t remember the last time I used it. A few days ago I wanted to use it and it wouldn’t start.It is fitted with a 1kW universal motor.

 

After investigating it is almost certain the speed controller is the problem. I started drawing the circuit of the PCB, but the makers have removed the ident information from the integrated circuit, so it doesn’t help in looking for what type of signal should be where. The board has mains connections on it so I don’t want to poke around without having done my homework. The driver is a triac part no BTA08, a 6A device.

 

Does anyone know any details of this machine’s controller? If I can fix it, I have a good machine.

[Alastair HParticipant @alastairh]

[john swift 1Participant @johnswift1]

Hi Alistair ,

 

If your lucky the IC could be some thing like a U208 or TDA1085C 

compare the data sheets with the control you have

 

U208 example circuit :- http://www.spelektroniikka.fi/kuvat/triacd.pdf

 

TDA1085C data :- http://www.onsemi.com/pub_link/Collateral/TDA1085C-D.PDF

 

TDA1085C is available from RS components

 

another option could be another speed control eg :-

 

http://www.quasarelectronics.com/cr0008-230v-ac-motor-speed-controller-modules-375w-750w-1500w.htm

 

John

Edited By john swift 1 on 07/06/2011 17:30:21

[Alastair HParticipant @alastairh]

Thanks for the reply John. Unfortunately it’s none of the above. I had been through the TDA devices, but no luck. The IC fitted is a 16 DIP, with a speed feedback connection on pin 12.

The gate connection to the triac is on pin 16. The triac A1 connection is to pin 1.

 

I could be really unlucky and find the device is a PIC or something equally exotic.

 

The chances are it’s not a faulty IC, but it would be better to know it’s supposed to operate before I attack it.

 

It may be worth having a word with Quasar as they might have an idea what it is. I have no idea what the speed sensor is though.

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