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Can you post a link to that Mississippi Ag Dept. discussion on this?
I'll probably get shot down on this idea, but here goes. Wouldn't a microwave oven transformer, powered with a portable generator in the boat work? Aren't the secondaries pretty high voltage?
For a given HT voltage, the shorter the distance between the ground electrode and the other electrode(s) the stronger will be the electric field. If the pond is deep, the ground electrode is at the boat and the other electrode(s) is/are at the pond bottom then the field will be weak. A stronger field would exist if all electrodes were at the pond bottom.
Possibly.Wouldn't a microwave oven transformer, powered with a portable generator in the boat work?
I read an ad for a high power fish stunner that outputs a 2 Joule, 2,000V pulse.
A standard ignition coil only outputs about a maximum of 100mJ of energy when used in the standard flyback mode.
To get higher energies you could use a capacitive discharge system.
If you charge a 1,600μF capacitor to 50V and discharge that through the primary of an ignition coil you would have a 5000V, 2 Joule pulse.
So you would need a DC-DC converter to go from 12V to 50v to charge the cap and then an SCR to discharge the cap through the coil.
The SCR can be triggered by a 555 astable.
Possibly.
But I would not power the transformer directly from an AC generator since the output would then be definitely lethal.
Likely the best way would be to charge a 300μF cap to 120V and discharge it through the 120V primary of a microwave transformer.
That would give a 2 Joule, 2,000V pulse, similar to the commercial stunner.
To operate from 120Vac you could use an SSR (solid-state relay) that has zero-crossing circuitry to generate one cycle of the 60Hz through the primary.
A 555 astable could trigger the SSR at the desired pulse rate.
The pulsed outputs would certainly give you a jolt you will remember, but it's not likely to cause death.
The capacitive discharge pulse design puts out a very short pulse.
You cannot significantly vary its width.
If you want a variable pulse width, then you would need to use a different design, such as driving a microwave transformer with pulses of AC.
So if you want a varying pulse width, then it would seem driving the μwave transformer from a 120Vac inverter with short bursts of the AC on the primary may be the way to go.
To vary the voltage you would have to vary the 120Vac from the inverter.
(Got a variac transformer?)
BTW: anybody have any advice on the best component combinations which work best with 555 timers?
a) capacitor/resistor
b) variable-capacitor/resistor
c) capacitor/variable-resistor
d) variable-capacitor/variable-resistor
Mica capacitors at 1uF and above are expensive ($4+ each) but are only 1% caps I can find...
(multi-layer mica caps wildly alter their values with physical shock (experience talking here))...
Tantalum capacitors seem to be more stable than common electrolytic capacitors, and don't cost much more...
(but they have that old "explosion/burning" thing with high ripple and/or spikes...)
Ceramic capacitors are stable over temp range, but physical shock can alter value (not as bad as multi-layer mica caps though)...
Air capacitors (variable) work great in high static fields and/or high emf zones, and extreme physical vibration/shock...
(but would need to seal/pot them some how)(non-magnetic, I've seen them actually mounted on transformers!)
Don't have much experience with any of the various poly caps, same goes for mylar caps...
Also, would the component combinations change between my needed circuits?
1) 555 astable circuits
2) 555 monostable circuits
3) 555 PWM circuits
4) 555 voltage multiplier circuits
All the circuits above need to operate in a wet/humid environment, with thoughts of safety in a metal boat on water...
(and physical shock without any doubt (boat paddles, transformer hum, big feet, etc...))
I very much desire to seal and/or pot as much of the circuitry as possible, keeping in mind this might affect the circuitry operation(s)...
With everything above in mind, I'm willing to pay more for components for stability, long life, and safety...
Just want extra expense to be justified...
(1% components are always nice, but not always really required, or even make ANY difference...)
Thanx in advance to all who take the time...
william...
For your cap problem, there are some things actually called 'pulse capacitors' made for this and fairly cheap from this place, https://www.surplussales.com/Capacitors/Polypropylene/Box-Caps/Index.html The MKP type are usually called pulse caps. No affiliation just a satisfied customer. They may have some of the other stuff you need.
https://www.surplussales.com/
Seems like my 'microwave transformer' idea wasn't so far off base after all. So here's another one, how about adapting a 'fence charger'? Some circuit changes would be needed to vary the pulses but it should be doable.
1% capacitors are only needed if you don't want to adjust the timing and that's not the case here, so even 20% capacitors would be fine.1% components are always nice, but not always really required, or even make ANY difference.
Most of those have a short, non-adjustable pulse width.how about adapting a 'fence charger'?