I find an old article from Nuts and Volts

[inservi1]

Hello,
A long time ago, I had a magazine Nuts and Volts which contained an article which described the driving of a small engine with a thyristor.
This review is old of more than 20 years.
I lost the magazine which contained this article. The diagram was very simple and functioned very well.

How can i do for find this article ?

Thank you in advance.

Best regards,

dro.

[jwax]

Welcome dro!
You're going to have to add detail if you want details. Small engine? An article about a thyristor? And this was around 1987???

[inservi1]

Hello Jwax,

Thank you for time that you want to grant well to my problem.

A very long time ago, I received this magazine from a friend. I do not buy it myself. it is then difficult for me to give the year of this article. but it is perhaps approximately 1977?

The article describes a very simple circuit to lead a small engine of DC (for small toys unless low tension 1A about 12V) with a thyristor and approximately 4 or 5 other components, a pot, some resistances, a condenser and perhaps a diac.
The pot was used for settle the speed of the engine.

Article's title , announce capacity to give the power to the engine at low speed. Or for start without jolt.

The characteristic for this time was to employ impulses to lead engine (PWM).

I suppose that the circuit is powered with CA.

I employed it for a small crane which I manufactured for a friend and it was perfect.

After several transformations in my house and a move, I cannot find my magazine

I am ready to buy all the collection between 1970 and 1980 to find this article!

Thank you and sorry for my bad English, I speak French.


Best regards,
dro.

[haklesup]

I don't have that artical but I can suggest you try a simple web search using the terms "SCR DC motor speed control"

I found this page with several examples
http://www.educypedia.be/electronics/powermotor.htm
Fortunately, some of the links are in French. Take a look and see if one looks familiar.

Also search on "Chopper speed control" or "Chopper DC motor speed control"

An SCR (thyristor) is not the only way to do it. A DC speed control can be dome with BiPolar or FET transistors just as well. Although it sounds like the circuit you want also has a Soft Start feature.

[inservi1]

Thank you Haklesup,

I already found the link that you have transmitted to me but i not found an equivalent circuit with SCR. There is one with triac bud i don't know if i can use it with SCR.

An SCR (thyristor) is not the only way to do it. A DC speed control can be dome with BiPolar or FET transistors just as well. Although it sounds like the circuit you want also has a Soft Start feature.

I already make my own MosFet H-Bridge driver for motors, controlled by a PIC with PWM and it is working well with smooth start and speed control but it is not as simple than the 'Nuts and Volts' one.

I continue to find a equivalent circuit with max 4 or 5 components.

Best regards,
dro.

[Lenp]

dro..

If you can give me a clue about what was on the cover, or other articles in the N&V issue, I'll look through my ancient stack to see if I can locate it.
Even without the clue, I'll look but it will take longer. There could be some missing issues but I'll give it a try.
Len

[inservi1]

Hello Len,

I just read your answer because there was summer vacancy.

I appreciate very much your help. It is really wondefull.

I need to make a big effort for remind some think from the cover page.

The image in my mind is very blurred but i think that a title is speaking about a 'smooth motor starting' or 'power at slow speed' ?

Thank you very much.

dro.