Topics

loading a booster for performance and thermal testing

jazzmanlj
 

I'll be building MERG boosters soon set up as 10A units. My thought is to drive it with a 8-10kHz square wave as opposed to a command station and use pure resistive load. This way I should be able to probe around and verify most waveforms and a good balance in the output drivers.

Any thoughts or comments on this approach appreciated.

Len Jaskiewicz

Mark Gurries
 

On Mar 12, 2014, at 3:06 PM, <len.jask@...> <len.jask@...> wrote:

I'll be building MERG boosters soon set up as 10A units. My thought is to drive it with a 8-10kHz square wave as opposed to a command station and use pure resistive load. This way I should be able to probe around and verify most waveforms and a good balance in the output drivers.

Any thoughts or comments on this approach appreciated.

Len Jaskiewicz
That would be a good test if it worked.

I do not know anything about this MERG boosters to know if it will work or not. So Boosters might look for a DCC packet protocol. Do not know. I know no harm will come of it if you try.

Best Regards,

Mark Gurries
Electrical Engineer
DCC Website & NMRA DCC Clinics: www.markgurries.com

jazzmanlj
 

Thanks Mark,

MERG UK has some pretty neat stuff as kits for very reasonable cost. Membership is needed but cheap. The boosters are $45 for a complete kit and I've verified that NCE users have them and work well. I haven't looked into the front end as to the driver chip and DCC packet protocol, but it just dawned on me I can bypass that and test the power output section. That's where the smoke and heat is.

I always look for a sanity check!

Len Jaskiewicz

Flash Gordon
 

Len

I do not understand why you would test it with out sending DCC packets. Isn't that the point?

Ed S

At 06:53 PM 3/12/2014, you wrote:


Thanks Mark,

MERG UK has some pretty neat stuff as kits for very reasonable cost. Membership is needed but cheap. The boosters are $45 for a complete kit and I've verified that NCE users have them and work well. I haven't looked into the front end as to the driver chip and DCC packet protocol, but it just dawned on me I can bypass that and test the power output section. That's where the smoke and heat is.

I always look for a sanity check!

Len Jaskiewicz

jazzmanlj
 


Len

I do not understand why you would test it with out sending DCC
packets. Isn't that the point?

Ed S
Ed,

DCC packets is not the primary point of testing!

The booster is a power device. The main output is a H-bridge configuration, typical of motor controllers. It has to first  be established that the power section is functioning as designed and at full power and there are no thermal issues with the switching devices. The testing should also include transient overloads to verify protection circuitry(I have over 30 yrs experience in switching power design).

Hope this helps your understanding as well as others.

Len Jaskiewicz

 

 

 

Flash Gordon
 

Thanks Len..

Yep eliminate variables.... continue and report.

Ed S

At 07:50 PM 3/12/2014, you wrote:



Len

I do not understand why you would test it with out sending DCC
packets. Isn't that the point?

Ed S
Ed,

DCC packets is not the primary point of testing!

The booster is a power device. The main output is a H-bridge configuration, typical of motor controllers. It has to first be established that the power section is functioning as designed and at full power and there are no thermal issues with the switching devices. The testing should also include transient overloads to verify protection circuitry(I have over 30 yrs experience in switching power design).

Hope this helps your understanding as well as others.

Len Jaskiewicz

Phil Euper <peuper@...>
 

Agree Ed.......Len, why not look at the output of the command station then put this output thru
the booster you built and look at it's output and compare the two outputs. If they
are same or close to the same you should have a successful build!

Regards

Phil Euper in SC

-----Original Message-----
From: Ed S
Sent: Wednesday, March 12, 2014 7:08 PM
To: WiringForDCC@...
Subject: Re: [WiringForDCC] loading a booster for performance and thermal testing

Len

I do not understand why you would test it with out sending DCC
packets. Isn't that the point?

Ed S

At 06:53 PM 3/12/2014, you wrote:


Thanks Mark,

MERG UK has some pretty neat stuff as kits for very reasonable cost.
Membership is needed but cheap. The boosters are $45 for a complete
kit and I've verified that NCE users have them and work well. I
haven't looked into the front end as to the driver chip and DCC
packet protocol, but it just dawned on me I can bypass that and test
the power output section. That's where the smoke and heat is.

I always look for a sanity check!

Len Jaskiewicz



------------------------------------

http://www.WiringForDCC.comYahoo Groups Links

jazzmanlj
 

,

Phil,

Wrong approach!

You probably missed my response to Ed as to why?

 

Like any piece of electronics being built testing has to start at a basic level to verify functions of the stages and progress to the final test. The command station signals are too complex for initial testing to verify good switching of the power H-bridge.

 

Len Jaskiewicz

 



 

Phil Euper <peuper@...>
 

Funny....I have looked at the DCC signal on my track with a scope
and the the output of my Command Station and they look
pretty much the same to my eye. Agree it is a complex signal
but seems to me we are just comparing real world scope
presentations here.
 
Regards
 
Phil Euper in SC
 
 

Sent: Friday, March 14, 2014 6:00 PM
Subject: Re: [WiringForDCC] loading a booster for performance and thermal testing
 


,

Phil,

Wrong approach!

You probably missed my response to Ed as to why?

 

Like any piece of electronics being built testing has to start at a basic level to verify functions of the stages and progress to the final test. The command station signals are too complex for initial testing to verify good switching of the power H-bridge.

 

Len Jaskiewicz