Well, I found the thread below...thanks AGAIN to DewCatTea-Bob...
After reading your post several time, I am still unsure what amperage the 160 is running at as well as what amperage the diode/rectifier has to be able to handle...
I found several of them here:
http://www.electronicsurplus.com/LeftNav/Semiconductors/SignalDiodes.catthat meet the minimum 71V but I still need to know the minimum amperage.
Thanks in advance for all your assistance...
Mark.
DewCatTea-Bob wrote:____ Sorta seems that I ought to help clarify some additional FACTS concerning diode-rectifiers for use on so-called "6-volt" DUKEs.....
__ I've used std.volt-meters to measure the maximum AC-voltage output of the alternators on most every OHC-single -('DUKE') model... Max.voltage ranged from about 50 to 80 RMS-volts -(for comparison, std.house-voltage is 110 to 130volts 'RMS' ! ) _ And "RMS" (RootMeanSquare AC-voltage) is considered to be the AVERAGE-voltage outcome of the std.AC-waveform, (that's fairly equal to the equivalent DC-voltage, [concerning 'resistance' loads, only]).
But in reference to diode-specs, "RMS" voltages need to be multiplied by the square-root of '2' in order to figure the 'PEAK'-voltage which a diode must stand-up against! _ Thus in order to be sure that a suitable diode will be able to maintain it's job on any stock DUKE model, the diode involved should have a PIV of at least 114-volts!
However in the case of the stock 160's relatively weak charging-circuit, a rating of 71-PIV should be quite sufficient for the involved diode's job, but, since diodes aren't made to meet such irregular specs, ya then have to choose an available unit which has what-ever diode-specs that'll cover -(even though exceed) the voltage & amperage figures which your required diode must contend with !
Likewise if ya can get a diode/rectifier unit with 100-PIV for a couple-bucks, or another with 200PIV (that's under just a buck -[1$] more, [and either choice can handle your minimum required amperage]), then ya could simply let your choice be determined by which-ever unit is easiest to get mounted (within your 160-charging project)!
___ What happens if a diode is subjected to conditions greater than it's rated-specs, ya may wonder!? ...
Well, when a diode's valve is performing it's job of preventing electrical-juice from REVERSE-flowing, and that juice develops excessive peak-pressure -(voltage-peaks that are more than 10% higher than the diode's rating), then the reverse-current will FORCE it's way though the diode-valve anyhow! _ And once that has occurred, the diode will then never be as good as it was when new! ... As it's valve will no longer be able to stand-up against the voltage/pressure which it was originally rated to handle,, or it may quit working all-together, by acting like either a 'short' or an open-circuit.
__ If a diode is simply exposed to a short-circuit and thus is then subjected to excessive forward-current-flow -(amperage that's over 10% greater than the diode's rating), then the diode will overheat & perhaps burn-out -(and that would then make it act as an open-circuit, [rarely as a short] ).
When a new diode is working near it's rated capacity, it will feel quite warm to the touch, but if it feels burning-hot, then something's not right!
Also, a diode's normal current-rating is set for room-temp operation, and so could handle somewhat higher juice-currents if kept cool, (such as by heat-sinking to metal kept below room-temp).
____ Furthermore, about "6-volt" DUKEs... The ONLY thing about any narrow-case model that's ACTUALLY '6' volts, is the 6volt-BATTERY & 6volt-lightbulb-FILAMENTs !
NO other part on any of them is really set at exactly '6-volts', not even the heavy so-called "voltage-regulator" black box which has "6 Volt" labeled right on it's side!!
Anything other than the 6-volt battery, is simply 'RATED' at 6-volts!
Enlightened-Cheers,
-Bob
