find a replacement capacitor

[jean-karim]

Hi folks,

I need to find a replacement capacitor for a toy RC, The car is from 1985... Capacitor refs that I found are : Ceramic kind of green cylinder capacitor 47ohm 5%, 73 little 2 beside, 2W.

Thank you!

 

[betwixt]

That means nothing at all I'm afraid. Capacitors are not measured in Ohms. Can you post a photograph of the part please, it sounds more like a resistor than a capacitor.

Brian.

 

[jean-karim]

Sorry, my bad, you are correct it's a resistor. Any idea of a ref to replace this damaged one I have?

 

[kam1787]

sounds like its 47 Ohms 2W
that's all you need to know to buy
if you have trouble sourcing, ask if they have 100ohms 1W, or 22 ohms 1W

 

[betwixt]

Expanding on what kam1787 stated - the 100 Ohms and 22 Ohms are not direct replacements alone, you would wire two 100 Ohms 1W resistors across each other (in parallel) to make it equivalent to 50 Ohms 2W and you would wire two 22 Ohms 1W resistors in line (in series) to make 44 Ohms 2W. Both are probably close enough to do the same job as the original. If you really want to be exact values you could use 150 Ohms and 68 Ohms in parallel to make 46.79 Ohms or use 39 Ohms and 8.2 Ohms in series to make 47.2 Ohms but if you do that, the heat distribution would not be equal and you would have to use 2W rated resistors in all positions.

47 Ohm 2W is a standard value/rating so you should be able to find the exact part quite easily.

Brian.

 

[jean-karim]

thank you guys!

The only strange stuff is why is this resistor so big with only 2 W?? about, 1.5 cms high 4mm width
all the ones I found for the same values are he classic tiny ones..?

 

[betwixt]

The 'classic tiny ones' are normally rated at 0.6W or less. The power rating is a measure of how much heat it can safely cope with, in general the higher rated ones use a coil of wire around a ceramic core while the lower rated ones use a spiral of carbon. As well as how hot it can be without damage, the other consideration is how much heat it can release into it's surroundings to keep from overheating. That is related to it's surface area which is why higher power ratings generally equate to larger physical size. If you use one of those small ones as a replacement it will almost certainly go up in smoke within a few seconds of operation.

Brian.

 

[jean-karim]

Do you have links for the exact replacement part I could get?

 

[betwixt]

You haven't said which country you are in, there are different suppliers from one region to another.

For examples go to: uk.farnell.com
Then in the search box at the top of the window type in "47 Ohm 2W" and select "through hole resistors" in the options that pop up. They are currently listing 26 different alternatives in stock! My preference would be to choose a "wire wound" type as they are more resilient to short term overloads.

Farnell (also known as Newark and as Element14) has distribution outlets all around the World.

Brian.

 

[Audioguru]

He is in Quebec, Canada. Bonjour.
Resistors can be ordered from Digikey or Newark in the US and they have warehouses in Canada.

 

[kam1787]

should be some electronic shops there! check the yellow pages for electronic components

 

[jean-karim]

Close Toronto , Canada in fact:-D, I stopped by The source ", radioshack back in the days and they don't even have stuff like this anymore! Anyway yes will either get it from some used boards or buy one online no big deal I guess.

Thank you all!

 

[Audioguru]

The Source sells cell phones. Guess who owns them now? Bell Canada of course.

There was Active Electronics but most or all their stores are closed now.

Sayal Surplus Electronics has two big stores in Missiassauga.

 

[jean-karim]

thanks lot! No wonder why Source is so boring now..., will check those shops in Mississauga

 

[Audioguru]

At Sayal in Mississauga I bought some Name-Brand very small 5V/2A switching power supplies made for powering modems for only $1.50 each and they are excellent. I also bought some Name-Brand clock radios for $1.75 each, they sound awful and the radio is not sensitive but they sound very good driving a larger external speaker system.

BUT, do not buy their no-name bag of LEDs from India because half of them do not work.

 

[jean-karim]

Thanks! will check this out!