A Confession

[DaveWM]

used a tripler not a quadrupler correct?

[Hagstar]

Originally Posted by DaveWM

used a tripler not a quadrupler correct?

It was a tripler yes, of course this is not literal though. Triplers don't use 3 stages for TV use, this was a 6 stage and there are 5 stage ones also. The waveform from the horz. output is so uneven that's what's needed to multiply the voltage 3 times. A quadrupler would put it near 30 kV, well above spec 25 kV.

What I used- http://www.ebay.com/itm/112011512150

John H.

[DaveWM]

Originally Posted by Hagstar

It was a tripler yes, of course this is not literal though. Triplers don't use 3 stages for TV use, this was a 6 stage and there are 5 stage ones also. The waveform from the horz. output is so uneven that's what's needed to multiply the voltage 3 times. A quadrupler would put it near 30 kV, well above spec 25 kV.

What I used- http://www.ebay.com/itm/112011512150

John H.

how do you know it put it near 30kv? is that assuming its being driven as it was designed vs how you are using it in this application?

[Hagstar]

Originally Posted by DaveWM

how do you know it put it near 30kv? is that assuming its being driven as it was designed vs how you are using it in this application?

Well the tripler is putting out 3 times the input voltage, 4 times would be near 30K. I would assume they are designed the same but the quadrupler would have 2-3 extra stages. As for design they are doing what they were designed to do as far as I can see- replace flybacks by turning horz. output voltage into high voltage- weren't they used this way originally at factory?

John H.

[old_coot88]

John, where you said:

Then I hooked up the tripler IN pin to the horz. output voltage terminal top of the assembly.

...does that mean it's going to the plate of the H out tube?

[Hagstar]

Originally Posted by old_coot88

John, where you said:

...does that mean it's going to the plate of the H out tube?

Yes, see photo of flyback in question earlier in thread. The top tab terminal goes to horz. output cap.

John H.

[old_coot88]

John, you indicated there's about a quarter-inch of the old HV winding (tire) still intact with the end tied off. Does the winding still have continuity? If so, possibly you could feed the tripler from the tied-off end, thus boosting the voltage going to the tripler. Just a thought.

[DaveWM]

Originally Posted by Hagstar

Well the tripler is putting out 3 times the input voltage, 4 times would be near 30K. I would assume they are designed the same but the quadrupler would have 2-3 extra stages. As for design they are doing what they were designed to do as far as I can see- replace flybacks by turning horz. output voltage into high voltage- weren't they used this way originally at factory?

John H.

I have only seen SS triplers used in SS circuits, so comparing the output of a SS horz transistor to the plate of a horz out seems like there could be some difference in the voltages applied to the tripler. On top of that I cant say for sure but I think they were attached to a winding on the fly back that was not at the same level as the horz out from the SS or tube if so used. So the fly could have been adding some beyond the horz out level.

Regardless IF you are maxed at 22.5v with no shunt current, and you are in the experimenting with using triplers to replace flybacks, then it would seem at least worthy of trying a quadrupler IF you want to get more HV. I suppose there maybe some other limits as to what you are getting out as far as power in/power out, but without trying I don't know if I would say it can't work. One last thing, 30kv is about where old flyback systems maxed out anyway, so if 4 times would be 30k you would be right on target for unregulated voltage.

[Electronic M]

Originally Posted by Hagstar

Well the tripler is putting out 3 times the input voltage, 4 times would be near 30K. I would assume they are designed the same but the quadrupler would have 2-3 extra stages. As for design they are doing what they were designed to do as far as I can see- replace flybacks by turning horz. output voltage into high voltage- weren't they used this way originally at factory?

John H.

An AC-DC multiplier is defined by it's number of diodes. A doubler has 2 diodes, a tripler has 3, a quadrupler 4, a quintupler 5, and so on. Thus a quadrupler can ONLY have one more stage than a tripler.

30KV unregulated should be fine...Some sets can hit 40KV if you disconnect the CRT and HV reg.

As long as you are not drawing more than about 1mA through the regulator with the CRT dark and the HV set to roughly 25KV, all should be well.

[Hagstar]

Originally Posted by Electronic M

An AC-DC multiplier is defined by it's number of diodes. A doubler has 2 diodes, a tripler has 3, a quadrupler 4, a quintupler 5, and so on. Thus a quadrupler can ONLY have one more stage than a tripler.

Here's a "Six stage tripler"- http://www.moyerelectronics.com/BVMo...c-83adfcdcb456

I'm sorry but this is incorrect for TV high voltage use and already covered earlier. That is quite true in pure science world. In TV use here a tripler is defined entirely by function. It is not at all like a textbook tripler based on stages, it's just what does the job of multiplying voltage times 3. In this case they don't work like in textbooks because of the irregular nature of the horz. output wave. As I explained before a "tripler" in this use NEVER has 3 stages, and quadrupler never 4. Triplers are in fact 5-6 stages. Here's a 5 stage tripler schematic I posted earlier in thread similar to the one I am using which has one more stage. These are not my ideas- they are data from forums explaining TV triplers. Normal rules regarding triplers don't apply in this case. It is not defined by the number of diodes.

[Hagstar]

UPDATE- I devised a corona free method of measuring high voltage (no there is no rubber cap on the lead to the CRT you can slip it under) and lo and behold I measure 22-24 kV out of her now. I didn't see the leakage robbing my voltage before where the tip of the probe met the (empty) rectifier socket contact. I sleeved it with 2 layers of shrink tubing leaving just the tip and voila- 24 kV which I adjusted per the specs down to 23.

John H.