Demonstration Cell - Variable Spacing Plate Cell

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Hi guys
 
I want to build the 8XA circuit but can't find the components suggested, I found a diode 1N1186 or a DSI35-08 it's a 800V 49 amp, a H11D3 only 200V.
Would those work instead of the others?
 
Thx

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Hi,
I am trying to replicate the 8XA variable plate setup but run into problems with the SCR. The GEC35M is no longer available so i am using a 2N6403G SCR instead. This has kind of the same properties as the original GEC35M used. The problem is however that the circuit only works on frequencies below the source frequency but above that the SCR just stays in the "ON" state and does not turn off anymore. With source frequency i mean 100Hz, ... as in 50 Hz AC rectified gives a 100Hz DC pulse. So below the 100 Hz the SCR turns on and of and i see gating hapening on the 100 Hz dc source. When i get above the 100 Hz i would expect the rectified ac pulses been split up into seperate pulses accoording to the pulse frequency. Anybody having the same problem? Have others been able to make the SCR switch above 100/120 Hz and split the rectified AC pulses in parts?


Regards,
Sharky

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@scalance
- The diode you mention is way over dimensioned, a 400V/16A would be more than enough.
- The H11D1 is still available at some suppliers but if you can not get them, ... i also use a MOC3043 optocoupler as a replacement


Regards,
Sharky

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@ Sharky
thx verry much for your reply bro, I found a spanish site and my ant will send them for me from there, but instead of SCR C38M I will use ECG5418 it's a SCR 400V 10A think it's enought too cause the cell will be only drawing  5A .
 
I tried to do the same thing as the 8XA using a 220v 32w bulb, 2 bridge rectifiers (one to rectify 110v from the transformer and the other as a blocking diode) it workes for a while I was happy with the results I got, but the day after I try it again and after a while the transformer and the bridge working as rectifier burnt out, I think this because the refctifier was not enought to handle it's a one found on an old pc power, but the one I used as blokcing diode is a 50A and still works.
 
I'm going to buy a new transfo and an other 50A bridge to rectify 110v this time and see if it's gonna handle this time.

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Nothing better than answering your own questions ....    An SCR will stay in the on status as long as the current does not fall below the holding current, ... even if the gate pulses are removed. Thus the seen effect that the SCR does not split the rectified AC wave into parts since during the wave there is still current so the SCR will not switch off. To make this work either the 8XA circuit is not complete (missing turning of circuit or second SCR) or there must be a GTO Thyristor used instead of an SCR. Any opinions on this??
Regards,
Sharky