Drill speed brake - How does it work? - Electronic Circuits Projects Diagrams Free

moody07747 · 20th June 2005, 11:35 AM

Last year I was given a craftsman 19.2 volt drill and was impress by the speed brake.

I had heard all about them but never had a drill that had the feature.

after all that I started to wonder how the speed brake on a drill worked.

one thing I found is that if I removed the battery and turned the drill by hand with my finger off the triger, the drill would be hard to turn, but if I turned the drill by hand with the trigger pressed, it turns easyer.

now that just confused me because that means that the speed brake does not use the battery as I thought it might?

so...How does this speed brake system work :?:

**Nigel Goodwin** · 20th June 2005, 11:48 AM

I'm presuming you mean 'brake' and not 'break' - which are rather different things!.

Some of the drills I've seen are purely mechanical, the motor is prevented from turning completely when you release the trigger - this allows you to better use a keyless chuck.

But assuming it's electrical braking?, all you do is place a short circuit directly across the terminals of the motor - this makes the motor FAR more difficult to turn - try it on any small DC motor!.

jrz126 · 20th June 2005, 12:09 PM

It possibly could short the wires going to the motor when the trigger is released?
If you try to spin a motor with the wires connected (shorted) it is pretty hard to turn.
Thats what I'm thinking from the way you describe it.

EDIT: I knew I should have refreshed this page

moody07747 · 21st June 2005, 05:00 PM

you guys are corrents

its a short between the motor terminals
i also tried this on a small DC motor and it does make it very hard to turn

thanks for that info.

Klaus · 23rd June 2005, 02:00 AM

Quote:

Originally Posted by moody07747

you guys are corrents

its a short between the motor terminals
i also tried this on a small DC motor and it does make it very hard to turn

thanks for that info.

Yes, agreed, but it only applies to PM (permanent magnet) motors. Most small DC motors these days are PM.

Klaus

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20th June 2005, 11:35 AM	(permalink)
moody07747	Drill speed brake - How does it work? Last year I was given a craftsman 19.2 volt drill and was impress by the speed brake. I had heard all about them but never had a drill that had the feature. after all that I started to wonder how the speed brake on a drill worked. one thing I found is that if I removed the battery and turned the drill by hand with my finger off the triger, the drill would be hard to turn, but if I turned the drill by hand with the trigger pressed, it turns easyer. now that just confused me because that means that the speed brake does not use the battery as I thought it might? so...How does this speed brake system work :?: __________________ Dave www.myspace.com/sonicorbstudios Welcome to "Sonic Orb Studios"

20th June 2005, 11:48 AM	(permalink)
Nigel Goodwin	I'm presuming you mean 'brake' and not 'break' - which are rather different things!. Some of the drills I've seen are purely mechanical, the motor is prevented from turning completely when you release the trigger - this allows you to better use a keyless chuck. But assuming it's electrical braking?, all you do is place a short circuit directly across the terminals of the motor - this makes the motor FAR more difficult to turn - try it on any small DC motor!. __________________ PIC programmer software, and PIC Tutorials at: http://www.winpicprog.co.uk

20th June 2005, 12:09 PM	(permalink)
jrz126	It possibly could short the wires going to the motor when the trigger is released? If you try to spin a motor with the wires connected (shorted) it is pretty hard to turn. Thats what I'm thinking from the way you describe it. EDIT: I knew I should have refreshed this page __________________ Jeff Zimmerman To the optimist, the glass is half full. To the pessimist, the glass is half empty. To the engineer, the glass is twice as big as it needs to be.

21st June 2005, 05:00 PM	(permalink)
moody07747	you guys are corrents its a short between the motor terminals i also tried this on a small DC motor and it does make it very hard to turn thanks for that info. __________________ Dave www.myspace.com/sonicorbstudios Welcome to "Sonic Orb Studios"