Tip for power regulator scheme

[Behemot]

Yo guys, just bough el'cheapo Tesco drill for like 10 Euro/12,5 USD bucks This thing does not even have power regulator under the button, it simply has on-off stages

And since anyway even on mainstream drills it is not precise enough for slow drilling using drill stand, I would like to make power regulation. It seems that simple diac-triac circuit is enough, but, there is plenty of them as usually. Could you please suggest me some scheme which would be good for more precise regulation? I do not need it to controll in 10 RPM range, but more like to be able to run slow speeds (like 100 or 200 RPM, not just 500, 1500 and full).

My drill is 500 W so in range like this it would be enough, but I think its just a matter of diodes and diacs/triacs used…there is not much price difference in between 3 and 6 A ones so thats OK to have some room And oh, I am 50 Hz grid

[ben7]

Re: Tip for power regulator scheme

Im ordering a small cheap drill from an electronics supplier too, and it has no speed control, so I need some sort of device to control the speed also xD
It was a good deal though, it includes drill bits and grinding wheels and buffing/polishing wheels

We could use a simple diac/triac circuit, or use the good 'ol LM555.

[budm]

Re: Tip for power regulator scheme

Just search for "TRIAC for motor speed control"
I.E.: http://electroschematics.com/444/mot...or-with-triac/
http://www.engineeringslash.com/digi...d-control.html

10A 600V or higher will be good enough for the drill.

Or more fancy stuff:
https://cdn.badcaps-static.com/pdfs/...5ba3a47725.pdf

[ben7]

Re: Tip for power regulator scheme

Just search for "TRIAC for motor speed control"
I.E.: http://electroschematics.com/444/mot...or-with-triac/
http://www.engineeringslash.com/digi...d-control.html

10A 600V or higher will be good enough for the drill.

Or more fancy stuff:
https://cdn.badcaps-static.com/pdfs/...5ba3a47725.pdf

Nice! Now just to find a triac and diac!

Do you think that circuit in the first link will work with 120VAC 60Hz?

[Behemot]

Re: Tip for power regulator scheme

Just search for "TRIAC for motor speed control"

Well I did, the thing is I found whole bunch of schemes So I am asking for one which you would recommend, for exaple that it is safer, handles the power better or stuff

[budm]

Re: Tip for power regulator scheme

You may want to buy the kit instead since parts are mounted on the PCB and the speed control pot has plastic shaft for safety. It will be a lot safer.
http://www.quasarelectronics.com/sma...ler-230vac.htm

[Behemot]

Re: Tip for power regulator scheme

I found localy some for 450 W, but…hey, I can do it for lot cheaper? We too have plastic potentiometers here

[ben7]

Re: Tip for power regulator scheme

I found localy some for 450 W, but…hey, I can do it for lot cheaper? We too have plastic potentiometers here

Plus it can be a learning experience (not the getting shocked part)

[budm]

Re: Tip for power regulator scheme

As you can see the schematic of the kit, it is not as good (filter wise) as shown in the link of the first diagram, so you can easily DIY from that first diagram I show in the link.
Here is another good info:

It gives both 230v and 120V operations.

[ben7]

Re: Tip for power regulator scheme

As you can see the schematic of the kit, it is not as good (filter wise) as shown in the link of the first diagram, so you can easily DIY from that first diagram I show in the link.
Here is another good info:

It gives both 230v and 120V operations.

Thanks, but the supplier I am gonna order some parts from soon only has TIC206D, could they be put in parallel or is that unsafe?

[budm]

Re: Tip for power regulator scheme

I am sure your supplier will have higher Voltage and Current rating available, you are in the US.
Since each TRIAC will have slightly difference trigger point, when you parallel them it does not guarantee that both of them will conduct at the same time. It will get real complex to parallel TRIACs.
Even RadioShack has them
http://www.radioshack.com/product/in...lickid=prod_cs
http://www.radioshack.com/product/in...uctId=13150194

[ben7]

Re: Tip for power regulator scheme

TIC206D can handle continuous 4A with 25A peak, your drill is only 500W @230V, so it will be less than 3A. I am sure your supplier will have higher Voltage and Current rating available.
Since each TRIAC will have slightly difference trigger point, when you parallel them it does not guarantee that both of them will conduct at the same time. It will get real complex to parallel TRIACs.

Ah ok.

The littelfuse pdf about triacs says that a minimum of 200V can be used for 120vac operation, and 400v for 240vac operation. In this case, the 400v triac will be fine then. But the question is, will it handle the current of the 500w drill at 120v? (I don't think it will)

BUT I think if I could use two 2N6507 SCRs in anti-parallel, they could handle it

[budm]

Re: Tip for power regulator scheme

I forget that you are in the US, so I updated my post 11, the TIC206D will not work.

[ben7]

Re: Tip for power regulator scheme

And no this particular seller doesn't have higher power ones, they mostly sell NOS stuff

So could I use two 2N6507 SCRs in anti-parallel? according to the internet, you need to use a triac to drive them, which can be of a lower power rating.

[ben7]

Re: Tip for power regulator scheme

And no this particular seller doesn't have higher power ones, they mostly sell NOS stuff

So could I use two 2N6507 SCRs in anti-parallel? according to the internet, you need to use a triac to drive them, which can be of a lower power rating.

Turns out I ordered from a different seller. I got one BTA316 triac and two DB4 diacs.

[ben7]

Re: Tip for power regulator scheme

Update...

I made this circuit, and viola! It works! My BTA316 has no problem dimming a 60w bulb! It doesnt even get warm with no heatsink on it. I will attach one when I build the motor speed controller though.

[budm]

Re: Tip for power regulator scheme

Great, just make sure to add that snubber network since you will be driving the inductive load.

[ben7]

Re: Tip for power regulator scheme

Great, just make sure to add that snubber network since you will be driving the inductive load.

Indeed

Gotta love dimmers, they put lots of noise back into the power grid
I can hear the two back to back 120v to 14v transformers (for isolation ) buzzing from the uneven current draw

[momaka]

Re: Tip for power regulator scheme

Update...

I made this circuit, and viola! It works! My BTA316 has no problem dimming a 60w bulb! It doesnt even get warm with no heatsink on it. I will attach one when I build the motor speed controller though.

Nice!

I need to build me some of these as well for various projects.

Although, come to think of it, would it also be possible to use chopped DC at 60 Hz (or 50 Hz depending on coutry) to drive a regular AC motor? If it is, then all you need is a bridge rectifier, a big electrolytic cap, and then hook that to a 555 -based PWM controller running at 50/60 Hz. Yes/no?? Experiment time?

[ben7]

Re: Tip for power regulator scheme

Nice!

I need to build me some of these as well for various projects.

Although, come to think of it, would it also be possible to use chopped DC at 60 Hz (or 50 Hz depending on coutry) to drive a regular AC motor? If it is, then all you need is a bridge rectifier, a big electrolytic cap, and then hook that to a 555 -based PWM controller running at 50/60 Hz. Yes/no?? Experiment time?

Possibly.

Experiment time!
I think you should send it a signal like in figure 4 on this page.
Also, note the full-bridge (also called H bridge) in figure 3.

I think you will need to make a full-bridge for powering the motor though.

BTW, crank the frequency up to make the motor go fast, but don't crank it up too much, don't want the commutator to shatter!