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A SCR stay open until the voltage at the gate go to 0v and below, if you place a 100k+ resistor between the gate and the ground that will switch off the scr when the zener/Neon close.
With a neon I don't think it would be such a problem. I did try a 2 k resister but that was not enough ?
Another problem is the zener keeps conducting as well I think. Thats why a higher value works better. SCR needs a minimum gate current to work properly as well, I don't think it's much though. A 1n5408 diode has 500k resistance from memory, does a diode not limit current like a resistor ? I've been wondering that.
Regards
So the 2k resistor to ground 0v probably took too much current from the gate not high enough value I see.
I just had a random thought, maybe having several large capacitors in paralell like a train, sets up a voltage difference wave from first cap to last, a flattening rising wave.
I was mistaken before my DMM had a low battery and was readin frequency wrong, the SSG is operating at one pulse per pass at 60 Hz so the ramped output pulses are at about 6 to 8 Hz.
I'm surprised it's still doing it, if it keeps going till morning it will help that poor battery.
A SCR stay open until the voltage at the gate go to 0v and below, if you place a 100k+ resistor between the gate and the ground that will switch off the scr when the zener/Neon close.
Best regards,
EgmQC
I do not agree with you, but at this stage i will try anything.
As far as i know once a scr is triggered it stays on till you either short it out or open the circuit or till the voltage on both sides becomes equal.
I do not agree with you, but at this stage i will try anything.
As far as i know once a scr is triggered it stays on till you either short it out or open the circuit or till the voltage on both sides becomes equal.
As I understand it with pure D.C. or even high frequency D.C. pulses, Nvisser is correct, however with pulsed D.C. that goes to zero or below for long enough commutation is forced, with A.C. this happens as the wave falls through zero volts and with an oscillator with clean breaks in the output it also happens.
Nvisser I was toying with the idea of a PNP transistor used in conjunction with the SCR, I think the animation posted above shows something like that.
Whatever the answer is I feel sure John Bedini has done it.
I do not agree with you, but at this stage i will try anything.
As far as i know once a scr is triggered it stays on till you either short it out or open the circuit or till the voltage on both sides becomes equal.
Its why even with a Neon you need a pull down resistor because the scr like a mosfet will stay On even when there no voltage at the gate.
Yes I can see the sense in that, As soon as I find a suitable resistor I will try it, "I like to try stuff".
So could I assume that the reason an oscillator can force commutation is because it pulls down the gate voltage ?
I don't think vissie was trying to be nasty or anything. Just stating his present thoughts.
EgmQC, I was thinking about trying a triac, I tried one before with some success it seems to make spaced pulses, I didn't get a chance to scope it, just the feeling I got. I ended up ruining it by connecting the load to the wrong terminal.
Do you think a triac would be benificial ?
Like Nvisser i'm willing to try anything to get reliable operation as desired.
Yes I can see the sense in that, As soon as I find a suitable resistor I will try it, "I like to try stuff".
So could I assume that the reason an oscillator can force commutation is because it pulls down the gate voltage ?
I don't think vissie was trying to be nasty or anything. Just stating his present thoughts.
EgmQC, I was thinking about trying a triac, I tried one before with some success it seems to make spaced pulses, I didn't get a chance to scope it, just the feeling I got. I ended up ruining it by connecting the load to the wrong terminal.
Do you think a triac would be benificial ?
Like Nvisser i'm willing to try anything to get reliable operation as desired.
Regards
I know vissie was not trying to be nasty.
You can use any software simulator to make this experiment if you want to see it without waiting for parts, will work on any software.
I relooked at my test setup and found something not really good , in my test setup i was making a voltage divider and its why that worked but was using 14W lol , 1M Ohm from (+) to gate and 10 Ohm from (-) to gate , was able to switch at will but the power consumption is crazy.
When ive done my cap pulser i used a mosfet , alot easier to work with since its DC impulse and no AC, just need to take care about the gate voltage to make it witch fully ON and to not put over voltage to it.
I see a simulator program would be sweet, when I install my new operating system I will get one and try to use it. more stuff to learn but it sure would save me some parts.
I came to the conclusion that I am not able to do this self switching without the help of a relay.
I will post here a relay circuit that did work but the contacts burned together in a few minutes.This thing was driven by a 8 filar solid state Bedini circuit like the patent I posted earlier. It charged the caps in series to 75V and with the diodes dumped it at about 18V to the battery.It was a monster!
The other simpler circuit I post is the way I think I will try it on Monday. Still using a relay, but the relay could be a small 12v relay and will not carry all the current. It is used to trigger the transistors. The cap over te relay coil is to keep it closed for a while and ccan be changed to a value that works best. I think it will work.
I am switching the positive here as I find it difficult to do it the other way round as it will need a pnp for the relay switching I think.
I came to the conclusion that I am not able to do this self switching without the help of a relay.
I will post here a relay circuit that did work but the contacts burned together in a few minutes.This thing was driven by a 8 filar solid state Bedini circuit like the patent I posted earlier. It charged the caps in series to 75V and with the diodes dumped it at about 18V to the battery.It was a monster!
The other simpler circuit I post is the way I think I will try it on Monday. Still using a relay, but the relay could be a small 12v relay and will not carry all the current. It is used to trigger the transistors. The cap over te relay coil is to keep it closed for a while and ccan be changed to a value that works best. I think it will work.
I am switching the positive here as I find it difficult to do it the other way round as it will need a pnp for the relay switching I think.
@Nvisser,
Ill post to you a simple solution with a mosfet, its what ive used with my ssg cap pulser. Ill not be here before late tonight but as soon as i get some time tonight or tomorow ill post a schematic.
Here the schematic, Ive put a simple 555 setup with it to illustrate a simple way to trigger the output side totally isolated but you can remove it totaly if you have a better way for the timing like a hall effect sensor triggered by a magnet or anything like that. The Diode is there to be able to have a really low duty cycle really sharp and it can be any diode , there praticaly no current flowing so even a really small diode will do the job.The delay is 1sec to about 3 sec but you can play with it , its only a simple 555.
I used a optocoupler to isolate the output side so you cant get reading error when you measure what is going on the output side from the leak of the 555.
On the output side thing cant be simpler, just take care at the max rating your mosfet is rated(you can use any mosfet , i just put a IRFZ44Z as example , its what i used but other mosfet will work too , depend on what you want it to do and the rating for the job it need to do).Just check for pins to not inverse it.
I will post here a relay circuit that did work but the contacts burned together in a few minutes.This thing was driven by a 8 filar solid state Bedini circuit like the patent I posted earlier. It charged the caps in series to 75V and with the diodes dumped it at about 18V to the battery.It was a monster!
Hehe that would have been a wild ride for the battery while it lasted. I'm confused by the method you use to swap from series to parallel, i'll try to understand it.
The other simpler circuit I post is the way I think I will try it on Monday. Still using a relay, but the relay could be a small 12v relay and will not carry all the current. It is used to trigger the transistors. The cap over te relay coil is to keep it closed for a while and ccan be changed to a value that works best. I think it will work.
I am switching the positive here as I find it difficult to do it the other way round as it will need a pnp for the relay switching I think.
Here the schematic, Ive put a simple 555 setup with it to illustrate a simple way to trigger the output side totally isolated but you can remove it totaly if you have a better way for the timing like a hall effect sensor triggered by a magnet or anything like that. The Diode is there to be able to have a really low duty cycle really sharp and it can be any diode , there praticaly no current flowing so even a really small diode will do the job.The delay is 1sec to about 3 sec but you can play with it , its only a simple 555.
I used a optocoupler to isolate the output side so you cant get reading error when you measure what is going on the output side from the leak of the 555.
On the output side thing cant be simpler, just take care at the max rating your mosfet is rated(you can use any mosfet , i just put a IRFZ44Z as example , its what i used but other mosfet will work too , depend on what you want it to do and the rating for the job it need to do).Just check for pins to not inverse it.
I like the look of that too. I need to order some more parts and buy some time
I really like to see the different ways things can be done.
Is there a particular simulator program that is more popular than others or better/easier to use? Suggestions anyone ?
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