Current Lover Issue

[Droogie]

Fired up my Current Lover build last night for the first time and R33 promptly started smoking (a first in around 50 builds). I immediately thought solder bridge to 9v+ but R33 is directly connected already. The 4001 next to R33 is oriented correctly and it's a bit hard to tell if it also was burnt.

I'll go through and check values and soldering per usual, but I'm a bit flummoxed by this. Any ideas generally of what I might have done wrong?

Also, is it likely I fried my MN3007?

Thanks!

[Govmnt_Lacky]

Sorry to hear about this... 

Are you certain that your R33 is a 10R resistor?

If it was smoking that could be an indication of your V+ being shorted to V- ANYWHERE. Since it is before the protection diode I am afraid that you will probably need to check the entire circuit.

Best bet would be to disconnect power and immediately check your resistance between V+ and V- (GND). If you are reading anything less than a few hundred ohms... you have a short somewhere.

Good Luck 

[midwayfair]

R33 is a current limiting resistor at the 9V input. It is used for noise reduction. 10R is fairly small and it's possible for high-current to simply pull too much across it, generate heat, and blow the resistor.

You could replace it with a jumper, or alternatively use a larger value (e.g. 100R) or higher wattage.

You are extremely unlikely to have damaged anything except the resistor.

[Droogie]

Are you certain that your R33 is a 10R resistor?

The resistor reads black, black, black, black, with a tolerance of 100% (black all over)  so I guess it's a 10R ! I'll try a higher value and replace D3—will also check for shorts  just in case.


Thanks for the help!

[jimilee]

In my etools legacy program, I can't find all black. weird.

[Droogie]

In my etools legacy program, I can't find all black. weird.

Just look under "burnt offerings" or "crispy critters".

[midwayfair]

In my etools legacy program, I can't find all black. weird.

Classic jimi!

[jimilee]

Ha! I'll be here all week, don't forget to tip your waitress.

[Govmnt_Lacky]

R33 is a current limiting resistor at the 9V input. It is used for noise reduction. 10R is fairly small and it's possible for high-current to simply pull too much across it, generate heat, and blow the resistor.

Agreed. Since the diode was a 4001, it is likely that the higher current draw did not effect it (4001 rated to 1A) and the 10R took the brunt of it.

You are extremely unlikely to have damaged anything except the resistor.

I might disagree here. If there was a direct short to ground somewhere in the circuit, the current flow "could have" traveled through one of the discrete components and damaged it. Or, one of the ICs, transistors, etc. could be the source of the short. HOPEFULLY NOT... but it is possible. Need to meter it all out.

[Droogie]

No harm in making sure there wasn't another short somewhere. I checked it out with the meter and all was fine. I'll try again tonite (with hazmat suit on).

Thanks again