How can a square wave generator be used in a resonance inductive circuit?

AI Thread Summary
A square wave generator built with a 555 timer can be utilized in a resonance inductive circuit, but it typically outputs low frequencies, which may require large inductors. For higher frequencies, small value components can allow operation up to 500 KHz. Users clarified the intent to create an inverting current for an electromagnetic induction coil, confirming that the output pin is pin 3. Precise electrical measurements may necessitate a divide by 2 flip flop due to the 555's inability to produce a true 50% duty cycle square wave. Additionally, incorporating a damping diode is recommended to manage high voltage spikes when driving inductors.
alpine2beach
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Square wave generator...what?

Okay, so I built a square wave generator using a 555 timer and schematics that I found off the internet. Upon completion, I dumbly realized that there is only an output. I wanted to use the square wave generator in resonance inductive circuit, but seeing as there is only an output, how would I be able to work it into the circuit? If not, how would it be used?
 
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You can take the output between the negative terminal of the supply and the "output" pin (pin 3) of the 555.

Could you explain what your mean by "resonance inductive circuit" ?

If you mean a series tuned circuit, then the 555 can drive such a circuit directly, although 555s normally generate quite low frequencies and tuned circuits for such frequencies would have large expensive inductors in them.

By using small value components in the timing for the 555, they can be operated up to 500 KHz or so. Maybe higher.
 


vk6kro said:
You can take the output between the negative terminal of the supply and the "output" pin (pin 3) of the 555.

Could you explain what your mean by "resonance inductive circuit" ?

If you mean a series tuned circuit, then the 555 can drive such a circuit directly, although 555s normally generate quite low frequencies and tuned circuits for such frequencies would have large expensive inductors in them.

By using small value components in the timing for the 555, they can be operated up to 500 KHz or so. Maybe higher.

Thank You! I know I didn't really word "resonance inductive circuit" correctly; I meant inductive coupling. I want to be able to create an inverting current using a 555 timer and dc current (such as a battery) to power an electromagnetic induction coil. And isn't the output pin pin#6? I guess it might depend on the manufacturer...
 


No, the output is always pin 3.

You probably need a circuit like this:

images?q=tbn:ANd9GcR97gDGJhcG4q3Y0sGJD40emIYouLU5DqvEGkqW5JXcy8CSb7JWIw.png


This shows a lamp in the collector circuit of a power transistor, but you would need the primary of a step-up transformer to be there instead.

This one is possibly more like what you would need:

images?q=tbn:ANd9GcRsmQlTqw9nt4OUYhcIiMqPGl_xfCSsxtejObVfUZ3_c9iHfEWbVQ.png
 


I think I must be misreading something... but where is the power supply (in image 1)?
 
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The 555 will not give you a true 50% duty cycle square wave, which you need to do precision electrical measurements. The 555 output should be put through a good divide by 2 flip flop.

Bob S
 


Quick note: If you drive an inductor as shown in the first pic above, there'll be high voltage spikes just as the transistor turns off. So you might consider a damping diode (a diode in parallel with the inductor and pointing upward, in the circuit shown)
 
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