Project: Simplest shocker

[ThermalRunaway]

Reading these posts about you lot striving to find newer and better ways to shock yourselves makes me realise that I'm not quite mad yet.

Brian

 

[Someone Electro]

A costumer taking a part a microwave? They dont even have the slistest idea of high voltage.Could lead to a lot of pepole death or in hospitals.

The cap is not all that bad the bas thing is tohgin the HV output of the transformer it can output kilowats and is certan to kill you.

A lot of pepole play whith these transformers beucse they have a huge output.Arcs from it are prety big.

 

[ThermalRunaway]

Yeah I agree, but from a customer's point of view, who probably doesn't have a clue about Electronics whatsoever, they're not going to realise that having switched off and unplugged the microwave, those caps are still carrying a fatal charge.

Brian

 

[Nigel Goodwin]

I remember having an argument with the service manager of our TV servicing department because he wanted customers to change the bulbs in their microwaves themselves rather than sending an engineer out to do it. This involved removing the cover and exposing the entire innards of the microwave on the models we were doing. He simply wouldn't believe me that it was completely irresponsible to suggest such a thing, I think he thought I was exaggerating when I explained that one touch of those huge capacitors would almost certainly mean death.

He was obviously a complete idiot!.

It's not even allowed to sell micro-wave bulbs to customers, unless it's an oven where you can change the bulb without removing the top. It's also an obligation to leakage test the oven if the top has been removed!.

 

[ThermalRunaway]

I didn't realise there was an obligation to leakage test the ovens if the cover was removed, but now that you've said it does seem quite obvious that you'd need to. I can tell you that our guys were changing the bulbs in microwave ovens very often, mainly because the customer's kept slamming the doors (and that's where the manager got his cost-saving idea from) but we never leakage tested any of the ovens afterwards!!!

Brian

 

[Nigel Goodwin]

I didn't realise there was an obligation to leakage test the ovens if the cover was removed, but now that you've said it does seem quite obvious that you'd need to. I can tell you that our guys were changing the bulbs in microwave ovens very often, mainly because the customer's kept slamming the doors (and that's where the manager got his cost-saving idea from) but we never leakage tested any of the ovens afterwards!!!

If you were offering micro-wave oven service presumably you were authorised to do so?, with engineers trained by the manufacturers?, with your facilities and equipment inspected at regular intervals?. One of the conditions imposed by the manufacturers is that all ovens must be leakage tested (with a yearly certified and calibrated meter) if the cover is removed.

To be honest they almost never leak, particularly as they are made to meet American standards, which are ten times less lenient than ours!.

 

[ThermalRunaway]

The truth is, I wasn't even trained at all! When I used to work in the field I just used my common sense when dealing with microwave ovens and, if it was anything more than changing a waveguide or bulb etc I'd book it into the workshop. Later I became based at the workshop doing the repairs that came from the field guys, and then I just used to avoid them completely. To be honest, I wasn't really interested in them - I was much more interested in new and complex technology like the latest camcorders, DVD systems etc. But no, we didn't have any of that training or inspections that you mention.

Brian

 

[HiTech]

The cap is not all that bad the bas thing is tohgin the HV output of the transformer it can output kilowats and is certan to kill you. A lot of pepole play whith these transformers beucse they have a huge output.Arcs from it are prety big.

Typically 4kv output from the Xformer for most avg. sized ovens. And most definitely, the capacitor is a critical point of harm to a person. It should be bled first before persuing anything else within the oven. Yesterday I just read a post in a home improvement forum where a homeowner wants to fix the noisy fan motor, inquiring for some advice. One replier advises him to use a screwdriver to short the caps terminals!!!!! Then he suggests to remove any sheetmetal nearby that could cause vibrations!!!!!! Hello!! Anyone thinking about the waveguide issue? Duuuh! I had to reply out of sheer concern for that homeowner's safety and life. I advised him to take it to a reputable oven service center and not fool with it.

 

[Someone Electro]

LOL!!! He would screw up big time.

 

[captaincaveman]

We've had a long running thread about this :lol:

As far as I'm concerned, pulsed DC is AC - the only practical difference is the DC level, which can be changed by simply passing it through a capcitor or transformer.

go easy on a newbie, whos trying to remember stuff, but i thought ac had to go through 0v to be ac? eg after ac goes through a bridge rectifier that hasn't yet been smoothed by caps its varying dc and not ac. hopefully you know what im trying to say?

 

[Nigel Goodwin]

go easy on a newbie, whos trying to remember stuff, but i thought ac had to go through 0v to be ac? eg after ac goes through a bridge rectifier that hasn't yet been smoothed by caps its varying dc and not ac. hopefully you know what im trying to say?

I know what you're trying to say, but there's no reason for AC to have to go through zero, or even down to zero - a sinewave swinging from +5V to +15V is just as much AC as the exact same wave swinging from -5V to +5V, the ONLY difference is the reference point. Display a sinewave on your scope, now turn the Y shift control, the trace has now DC shifted - is it still AC?, of course it is, only the reference has changed.

Your bridge rectified waveform will pass through a capacitor or a transformer just as easily as the original waveform, in fact through a capacitor BETTER, as it's double the frequency.

 

[Hero999]

Never put DC through a transformer - it will saturate.

What you're talking about is AC + DC, not pure AC which must go through 0V.

 

[captaincaveman]

Never put DC through a transformer - it will saturate.

What you're talking about is AC + DC, not pure AC which must go through 0V.

no sorry what i mean was say a basic power supply for example, first mains ac, through a transformer to say 30v ac then through a bridge that chops the bottom off sine wave so it looks like this(sort of, half rectified) _n_n_n_ (couldn't find right symbols on keyboard )or nnnn_which is double frequency, but cause it doesn't go back and forth as it did before bridge(when ac), i thought thats what a very rough dc was, before rough smoothing with a capacitor or regulator etc

hope ive written that better?

 

[Someone Electro]

We dont need full wave AC.If you just thurn on off a transformer will run.You may even get higher voltages because inductive kickback steps in.

All a transformer needs is a varying voltage.The output is just noisyer if you drive pulesd DC in.You just must not use too high freq. pulesd DC becuse then the tranfromer will begin taking it as DC and overheat.

 

[HiTech]

how can I make my body to conduct this current? I mean, make myself the shocker? without having somone touch anything apparently, just myself.

Let me get this straight in my mind. You want to "touch" yourself, confused: ) and get shocked simultaneously? OK here's how: thoroughly wet both hands in saltwater. Then with one hand firmly gripping your 'nads, place the other hand on a live spark plug wire, and your wet tongue on a battery terminal. It's even more effective if you can do this using a U.S. military vehicle that uses the 24volt system.

 

[audioguru]

For an unknown reason (maybe because he is just a little kid) he wants to be a shocker. He wants a big spark to come from his finger to shock other people around him. I presume that he doesn't want to feel the shock himself.

Do you think he should carry around a Van de Graff generator to do this??

Electronically, can a high voltage generator circuit shock somebody with only a single wire?? Then maybe the other "wire" can be capacitive coupling to ground by the circuit and the person receiving the shock??

 

[HiTech]

LOLOL! A Van de Graff generator toted around in a backpack!! A Tesla coil would do well too. He can wear one of those chef's carving gloves made of chainlink mesh. Let's hope his first victim doesn't have an implanted pacemaker!!

 

[ZIGGY_DAN]

In my opinion pulsed DC is NOT AC, AC stands for alternating current, i.e. it flows one way then another, it alternates. If you have pulsed DC then the current flows one way and since the load resistance does not vary but the voltage drops then the amount of current flowing reduces but does not reverse direction as with AC whereby the potential goes below 0V and the current begins to flow in the opposite direction.

 

[Nigel Goodwin]

You are quite entitled to your opinion, but how does applying a DC shift to an AC waveform suddenly prevent it from being AC? (likewise, how does simply passing it through a capacitor 'magically' make it AC again?). In BOTH cases electrons flow in alternating directions, it's only how far each way, with regard to a specific reference point, they flow that changes.

 

[Someone Electro]

Well a trasformer will be hapy whith pulsed DC or AC so dosent mather.Its basicly the same thing exspet pused DC has a ground lower for half of its amplitude.