What is the difference in capacitors with the same rating? On the computer I put in .47 400V capacitors and came up with several capacitors with this rating and varied prices from .75 cents to $8.
I am not an electronics person so plain language works best.
I do remember being automotive college 60 years ago and having some one charge up a condenser and finding it in your shop coat pocket when you reached in. You do not forget those things.
Capacitors
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Dennis_Brown
Topic author - Posts: 245
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TRDxB2
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Re: Capacitors
Read this https://byjus.com/physics/capacitor-types/
It explains these types
Ceramic Capacitors
Film Capacitors
Power Film Capacitors
Electrolytic Capacitors
Ceramic capacitors
Film capacitors
Paper Capacitors
Electrolytic capacitors
It explains these types
Ceramic Capacitors
Film Capacitors
Power Film Capacitors
Electrolytic Capacitors
Ceramic capacitors
Film capacitors
Paper Capacitors
Electrolytic capacitors
The past is a great place and I don't want to erase it or to regret it, but I don't want to be its prisoner either.
Mick Jagger
Mick Jagger
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Chris Barker
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Re: Capacitors
If you are asking in connection with Model T coils, the important parameter is what is termed dv/dt.
This is the device's ability to survive a rapid voltage rise - hence change in voltage divided by change in time.
Most ordinary capacitors are unable to work very long in the T coil environment. The red or orange ones sold by vendors do.
This is the device's ability to survive a rapid voltage rise - hence change in voltage divided by change in time.
Most ordinary capacitors are unable to work very long in the T coil environment. The red or orange ones sold by vendors do.
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Ron Patterson
Re: Capacitors
Dennis
Various capacitors types cited above by Frank are designed for specific circuit electrical charteristics. Costa are all over the map.
As Chris points out above the critical Dv/Dt specification (rate of change of voltage/rate of change in time, expressed in volts per micro seconds) is the key charteristic that is absolutely required to operate in the Model T ignition coil circuit because of the high voltage peaks that occur during normal operation.
This type capacitor were commonly used in switching power supplies and television flyback transformers. Few circuits with those charteristics are used today. Hence, you could easily find them in small quantity, but not so much today. Ten years ago and earlier you could easily find a .47 Ufarad/400wv capacitors with a Dv/Dt rating over 600 volts at a reasonable price and use them to rebuild coils. Today, if you want these capacitors, unless you can may some NOS parts at a cheap price, you can also find a few capacitor manufacturer who still make them to order and the cost can be prohibitively high based on the small quantity needs of Model T hobbyists to rebuild coils. If you order a quantity of 20,000 units from capacitor manufacturers you can get a reasonable price, but that buy will cost you approximately $20,000.
I recently posted some NOS coil rebuilding capacitors for sale in the classified section of this Forum , but there was little interest. I might have set the minimum buy a bit high for most?
Various capacitors types cited above by Frank are designed for specific circuit electrical charteristics. Costa are all over the map.
As Chris points out above the critical Dv/Dt specification (rate of change of voltage/rate of change in time, expressed in volts per micro seconds) is the key charteristic that is absolutely required to operate in the Model T ignition coil circuit because of the high voltage peaks that occur during normal operation.
This type capacitor were commonly used in switching power supplies and television flyback transformers. Few circuits with those charteristics are used today. Hence, you could easily find them in small quantity, but not so much today. Ten years ago and earlier you could easily find a .47 Ufarad/400wv capacitors with a Dv/Dt rating over 600 volts at a reasonable price and use them to rebuild coils. Today, if you want these capacitors, unless you can may some NOS parts at a cheap price, you can also find a few capacitor manufacturer who still make them to order and the cost can be prohibitively high based on the small quantity needs of Model T hobbyists to rebuild coils. If you order a quantity of 20,000 units from capacitor manufacturers you can get a reasonable price, but that buy will cost you approximately $20,000.
I recently posted some NOS coil rebuilding capacitors for sale in the classified section of this Forum , but there was little interest. I might have set the minimum buy a bit high for most?