Simple DC Injection Braking Circuit: Please have a look at the circuit diagram attached. I am writing a technical article and wish to authoritatively quote the correct patent number for this circuit. So far my searches have eluded me. Does anyone know of it or else can provide more information as to the technique's origins (i.e. names, dates. etc). I suspect it would have to be around the 1950's or before.

 

Are you sure that is under patent, that circuit has been around in general use for some time.
Max.

 

Are you sure that is under patent, that circuit has been around in general use for some time.
Max.

Hi Max, Please, tell me MORE, MORE!! Seriously, what do you know of its history? (I would be highly surprised if there was no patent) Kind Regards.

 

Have you checked the prior art cited in these U.S. patents?

2,413,070 Reeves _____________ _.. Dec. 24, 1946

2,606,312 Rogers _____________ .._ Aug. 5, 1952

2,821,639 Bright et \al. _________ __ Jan. 28, 1958

1,976,562 Janisch ___________ __ Oct. 9, 1934

2,167,530 Schneider ________ __ July 25, 1939

2,264,333 Satterlee _________ __ Dec. 2, 1941

 

If the patent dates back to the 50's it has expired and is no longer enforceable.

 

we still had some grinders around here with tubes to time the dc injection. if that gives you any idea of how old the patent might be.

 

Looks like a simple DC injection circuit for producing dynamic braking in an induction motor.

The patents on this arrangement were probably issued during the earlier days of electricity after Nicola Tesla introduced AC power.

 

Have you checked the prior art cited in these U.S. patents?

2,413,070 Reeves _____________ _.. Dec. 24, 1946

2,606,312 Rogers _____________ .._ Aug. 5, 1952

2,821,639 Bright et \al. _________ __ Jan. 28, 1958

1,976,562 Janisch ___________ __ Oct. 9, 1934

2,167,530 Schneider ________ __ July 25, 1939

2,264,333 Satterlee _________ __ Dec. 2, 1941

 

Hi Dick, Thanks for taking the time to reply. Unfortunately none of your quoted patents are of any use since they relate to DC motors, not AC Induction Motors. I'm still hopeful someone will deliver the goods!

 

If the patent dates back to the 50's it has expired and is no longer enforceable.

I know all that! What I want to know is the patent number! Someone must know......

 

Looks like a simple DC injection circuit for producing dynamic braking in an induction motor.

The patents on this arrangement were probably issued during the earlier days of electricity after Nicola Tesla introduced AC power.

It might very well be simple, but it's actually very subtle. Think about it....!