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Problems with the construction of the Slayer Exciter...

Andremaia

Jan 31, 2018
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Hello everyone reading this post! First of all, I don't understand a whole lot of electronics... In fact, I just started out... I'm a student and I stumbled upon this project called "the slayer exciter" and I'd like to make it work for the science fair at my school.
As you may have guessed it didn't work that well and that's why I'm here, hopefully I'll get this fixed before the delivery...
This is the circuit:
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For the seconday coil, I used a PVC pipe with about 2.5 cm of diameter(1 inch) and 9 cm of height(3.54 inches) and winded the coil all the way down, for the Primary coil I wound up 4 turns in the opposite direction of my secondary coil.. I used a 2N2222A transistor and I think I connected the ports correctly ( My transistor gets really hot within a few seconds of the circuit being turned on ) I used a 22k resistor.

I have some questions regarding electronics as well.
1. Can I use common copper wire to connect my circuit? ( my cables had a bunch of little wires instead of a solid grey wire. )
2. And shouldn't this circuit be wrong as it's open?

Thanks in regards, André
 

Harald Kapp

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Nov 17, 2011
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1. What do you mean by "to connect my circuit"? The coils are best wound from so called magnet wire.
2. The circuit "uses" the implicit capacitance from the output (open end) of the secondary coil to battery minus.

You may check:
1. Is the 9 V battery o.k.? This circuit will draw a lot of current and battery voltage will break down fast.
2. Did you try swapping the ends of teh primary coil as suggested by many online "instructions" for this circuit?

The operation of the circuit is described e.g. here.
 

Audioguru

Sep 24, 2016
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I do not expect the LED to glow. It is used as a voltage clamp so that the negative voltage pulse given to the base of the transistor does not exceed its voltage rating.
 

Andremaia

Jan 31, 2018
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I do not expect the LED to glow. It is used as a voltage clamp so that the negative voltage pulse given to the base of the transistor does not exceed its voltage rating.
I thought it was optional so I didn't even use the LED, is it advisable for me to use it?
 

Harald Kapp

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The LED is not optional. It creates a return path for current from the secondary coil. Any diode will do if you not have an LED at hand.
Always tell us the whole truth - lacking the LED your build is different from the schematic shown. You cannot expect to get good answers in such a case.
 

Andremaia

Jan 31, 2018
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The LED is not optional. It creates a return path for current from the secondary coil. Any diode will do if you not have an LED at hand.
Always tell us the whole truth - lacking the LED your build is different from the schematic shown. You cannot expect to get good answers in such a case.
Ah! Thanks :=) that should be my problem then!
 

Andremaia

Jan 31, 2018
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Ah! Thanks :=) that should be my problem then!
I ended up fixing my problem by switching the terminals of my primary coil as you said, weirdly enough the circuit did work without the LED, can someone explain me why it works?
 

Audioguru

Sep 24, 2016
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The 2N2222A transistor has a base-emitter maximum voltage rating of -6V. If it gets more than 6V then it breaks down and conducts like a diode so the circuit works. But the breakdown slowly destroys the transistor which is why it has that low voltage maximum allowed rating. The LED or any diode conducts at a few volts instead of the transistor being destroyed.
 

Andremaia

Jan 31, 2018
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The 2N2222A transistor has a base-emitter maximum voltage rating of -6V. If it gets more than 6V then it breaks down and conducts like a diode so the circuit works. But the breakdown slowly destroys the transistor which is why it has that low voltage maximum allowed rating. The LED or any diode conducts at a few volts instead of the transistor being destroyed.
If I was to fork this circuit without the diode would I be needing a beefier transistor?
 

Audioguru

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ALL transistors have a low maximum allowed base-emitter reverse voltage. Adding a cheap diode or LED prevents it in this circuit.
 
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