Capacitors vs Condensers?

Hi All.

Came across the following:

ELNA 3 mfd 15 vdc condensers &

Tosin Japan 50 uf 12v condensers.

These examples are cylindrical, colored grey with a wire coming out of each end & one end marked "+".

Are these Capacitors?

Can they be used when building or upgrading loudspeaker crossovers?


Thanks.

Cliff
 
Hi All.

Came across the following:

ELNA 3 mfd 15 vdc condensers &

Tosin Japan 50 uf 12v condensers.

These examples are cylindrical, colored grey with a wire coming out of each end & one end marked "+".

Are these Capacitors?

Can they be used when building or upgrading loudspeaker crossovers?


Thanks.

Cliff

They are caps, but their voltage is too low to use in crossovers, 100w is 28.28v RMS in 8R and 20v RMS in 4R. Best is to use caps that can handle at least 50v for hifi speakers up to 100w and 100v for speakes up to 600w.
 
Line level inputs are often 1 uf or 4.7 uf. 3 uf is in the middle.
Amp circuits often have 47 uf 50 v caps in the front ends. My CS800s is full of them.
If it has a plus on one end, or NP after the voltage rating, it is an electrolytic cap. An aluminum bottle filled with water slime and sealed with rubber.
Aged electrolytic caps are often frustrating to use, as the rubber seal deteriorates on the shelf from exposure to oxygen. I got 2 operating cycles out of an exact match cap for my ST70 I bought from surplus house stereocostcutters, ending with a puddle of cap slime in the bottom of the amp and a blown $1 fuse. Buy from a distributor as farnell, digikey, mouser, arrow, RS, reichelt, to avoid doing the job twice. If you buy their discounted stock, it is past shelf life and needs to be reformed by charging up through a resistor before use. I use a 12 v battery charger and a 47k resistor. Any extras I bought to save freight are past shelf life on my parts shelf, anyway. I buy only 3000 hour up service life caps anyway, which reduces the effect of unpowered aging since they weren't made of cheapo rubber. If you don't ask, you get 500 hour or 1000 hour service life caps from most shops.
 
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Thanks.



Is there anything hifi related where these condensers can be used?



If they are old elco’s i would not use the anywhere as they are probally dried out and far out of spec due to aging. When they are filmcaps, you could use them in preamps on the input as dc stopper or on tube heater circuits maybe. But best is to use at lest 50v caps everywhere
 

Galu

Member
2018-04-17 6:50 pm
...one end marked "+". Can they be used when building or upgrading loudspeaker crossovers?
Just to be absolutely clear Cliff, you are describing polarised electrolytic capacitors (one end positive and the other end negative). Only non-polarised (NP) electrolytic capacitors can be used in loudspeaker crossover networks. All types of plastic film capacitors are NP, and are the types favoured for use in today's loudspeakers.
 
capacitors where sometime incorrectly labeled:
mFD rather than uF
I'd say the committee that made up "u" for micro is the most incorrect. They couldn't speak English, and they could't write the Greek alphabet correctly, either. Mu has a tail on it; it is not the same letter as the english u.
These capacitors labeled "mF" are really old, and should be used only briefly in prototypes. Wear safety glasses using them: they might explode, and the tops might not have the modern pressure relief scoring either.
 
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12v condenser? SOunds like a cap meant for automotive use. But surely they would be fine as cathode bypass caps. I used to regularly see things like 10uf 6v lytic caps in that use.

COndenser is just the old word for capacitor. Main word:eek:ld. I suspect these are way past their prime.

I'd say the committee that made up "u" for micro is the most incorrect. They couldn't speak English, and they could't write the Greek alphabet correctly,

oh come on. Typewriters in English don't HAVE mu or other Greek symbols. And from any distance at all, that lower case u looks an heck of a lot like a lower case mu. I doubt they had trouble writing Greek, they just didn't have Greek symbols to use on schematics. And who says they couldn't read English.

Back when, a Farad was just a concept, and actual whole farad cap would be the size of a house. so millifarad was unlikely as well. In the old days, mf meant micro-farad...mf. And pico was something scientists used, but we used micro-micro-farad for small caps, and that was abbreviated mmf, which became uuf. And then they decided thatwe really should be using pico instead, and that is how we got to pf.

And M meant thousand way back. I recall some OLD Gibson drawings where the resistors all had M instead of k. SO a 100k plate resistor was written 100M plate resistor. At first the drawing looks like an amp full of multi-meg resistors. "Where will I find a 500 meg volume pot?" But it was just 500k after all.
 

Galu

Member
2018-04-17 6:50 pm
My uncle was a manager at the Telegraph Condenser Co. Ltd (TCC) in Bathgate up to 1965 when it was taken over by Plessey and became Plessey Capacitors Ltd. The factory closed in 1982.

My uncle took me on a tour of the factory when I was still at school. I didn't really know what a capacitor was then, but was enthralled by the banks of winding machines consuming rolls of waxed paper and metal foil at breakneck speed!
 

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