I have now seen two 2465 PCB blocks with a burnt-out on/off switch.
The damage is caused by the arcing across the now-separating terminals, when the machine is switched OFF.
Replacement is easy with NE182UEEP6AMP, but examining the circuit shows me that this failure could well be preventable with the addition of either a single ceramic snubber capacitor of between 3.3nF to 10nF (example Vishay¡¯s VY1 or VY2 series), OR an R+C snubber network ¨C I calculated a 120 ohm 2W ceramic comp in series with a 33nF X2 film cap, across the Tek switch¡¯s on-off terminals.
What are the considerations for selecting EITHER a single ceramic cap, OR making up a R+C snubber?
I¡¯m not looking at the apparent cost savings of installing a single cap vs constructing a R+C.
The objective is long-term reliability.
Also, how would one select the capacitance value of the single ceramic cap?
I¡¯m thinking of applications on vintage stereos.
I noticed that a new Yamaha hi-power stereo uses a 10nF, and a 20-year old CD-player uses a 3.3nF.
Is the current draw a factor?
Over to the experts¡.
Menahem
