Oscillator

The experimental inductor coil in the circuit above is actually a bobbin type 1.5" inches outside diameter by 0.75" inches inside hole diameter and is 0.5" inches in depth. I've close wound on it 200 turns of 20swg insulated copper wire. I've no way of working out its inductance ( L). The capacitor ( C ) value can be any to hand which I can try. The inductors core ( L ) is a high strength neodymium magnet.

1) Would this 555 oscillator circuit work with the added inductor coil ( L ) & capacitor ( C ) in the MOSFET drain, and, would this enable me to tune the output frequency of the 555 timer to the resonance of L & C . If the circuit is actually workable would the diode D3 be necessary or would it just clip the resonance?

2) What would be the effect of having this strong neodymium permanent magnet as the inductors core and would its radiated field strength ( Flux ) increase at the circuits pulsed resonance.

3) What realistic frequencies might be achieved with this configuration, based on the fact that the CMOS 555 has a maximum output frequency of 2.7Mhz.

4) Could capacitor "C" be made variable to "alter / tweak / adjust" the tank circuit after it reached resonance via the 555 timer.

5) If the capacitor "C" was removed from the above configuration but the inductor coil "L" was left in with the diode D3 across it, what type of waveform would be showing across "L" .

The schematic below represents (hopefully) the basic schematic of above with a 3 way switch SW1a & b and selective inductors / capacitors as "tanks" on the output stage for each frequency created by the capacitors C1, C2, C3 on SW1a.

I need advice on ferrite being used as cores for each of the inductors rather than using a fixed neodymium magnet as in the top schematic. How much magnetic flux could be produced from such coils at different frequencies upto the cutoff frequency of the LM555 timer (2.7Mhz).

Also could each individual inductor / tank produce a magnetic field in excess of 10,000 gauss throughout the frequency range. I hope I've got the magnetic terminolgy correct here.

Would the circuit timer operate more equally if just a variable resistor of say 47K was placed across pins 6&7 on the LM555 IC instead of the 1N4148 configuration as shown below etc.

A forum member LJCox has been helping me considerably and HERO999 asked what the purpose of the circuit was. If you can use this link below and read the communications it will probably help you:

Hi everyone,

Sorry for the delay in answering, grandkids are very demanding !!

The circuit is actually off the internet with the INDUCTOR (L) coil added to the output stage. This is the actual text from the author:-

"The output voltage from pin 3 of the second NE555 chip is reduced by the 220 ohm / 820 ohm resistor combination. The transistor acts as a current amplifier, capable of providing several amps to the output electrodes.
The 1N4007 diode is included to protect the MOSFET should it be decided at a later date to introduce either a coil (“inductor”) or a transformer in the output coming from the MOSFET, as sudden switching off of a current through either of these could briefly pull the ‘drain’ connection a long way below the 0 Volt line and damage the MOSFET, but the 1N4007 diode switches on and prevents this from happening by clamping the drain voltage to -0.7 volts if the drain is driven to a negative voltage."

I kind of understand this but I'm a real novice where electronics are concerned, hence the request for forum members help.

From my personal perspective, I was hoping to drive the Inductor coil (L) with pulses of varied frequencies via the 555 and the MOSFET and add these to the static magnet field of the (L) coils neodymium magnet core surface. This neodymium magnet core actually has a static gauss strength of 10000 and I was hoping to add the circuits output to this and create a pulsed radiation field. I want to then apply those varying increased pulsing fields to biological matter and view any changes which might take place in such.

Freaky stuff eh? Well not really, magnets and magnetic pulsing has been used quite openly to assist injuries to bone breaks etc, and give pain relief due to its apparent anti-inflammatory action. Football physiotherapists use low & high frequency pulsers daily to aid healing on their players. There's a new field of Electro-medicine which is testing various pulsing magnetic devices on Cancer and tumour lines. Now that's interesting.

There you go Hero999 and friends, the full story in a nutshell. maybe the "nut" of the latter word is applicable to me, who knows?

Oh yes, I now realise I don't have to add a time stap to my posts. Thanks for that, my inexperience shines through once more!

Speak soon,

John

Thanks for your time, I'm afraid I don't have access to an oscilloscope and such.