http://www.redcircuits.com/Page18.htm

polyester capacitors are not available. can i use ceramic caps of same value. aur any other value which is suitable for this circuit. Also, is there any equivalent of ic 4093?

 

hi SM,
The 4093 is a CMOS device, so a 74HC132 would be suitable.
E

 

Hi Eric
thanks for hc132. But can i use ceramic capacitor of same value instead of film capacitors?

 

hi SM.
It will work with ceramic caps.
As you may know film caps are more temperature stable than ceramic.

E

 

As you may know film caps are more temperature stable than ceramic.

NPO dielectric ceramic caps are quite stable with temperature but are only available in smaller sizes, up to a 0.1μF or so, compared to the X--, Y-- dielectric ceramics that go to several μF.

 

There is nothing about this circuit that requires any specific capacitor type; use whatever you have. Also, since it is a 3 V circuit, you do not need 63 V or even 25 V capacitors. Anything rated 10 V and above is fine.

The CD4093 does not have a direct replacement in another technology, which has been very frustrating for many years. You can use a 74HC132, but it has a different pinout for half of the gates.

ak

 

NPO dielectric ceramic caps are quite stable with temperature but are only available in smaller sizes, up to a 0.1μF or so, compared to the X--, Y-- dielectric ceramics that go to several μF.

The TS did not specify NPO ceramics.

 

I wad trying to make this electromagnet with 35 gauge wire and approx 500 turns on 4cm long iron rod, approx 6mm in diameter. When i connect this to 9V battery, it doesnt produce any magnetic field neither get warm. but when i check battery volts during connection with multimeter it drops to 30-50mV. All turns in clockwise direction from 1 end to 2 and 2 to 1 end. Still, not working.

 

hi SM,
Measure the resistance of your coil.
E

 

Does that wire have an enamel insulating coating, or is it bare copper? You can test this by touching ohmmeter leads to the side of the wire rather than to the cut ends.

ak

 

The 9V battery probably has too high of an internal resistance to supply enough current to your coil.
Typical 9V batteries have about 2 ohms of internal resistance, I'll bet your coil resistance is lower than that, basically 'shorting out' the battery.

Also, beware of wrapping the wire (assuming its enameled copper magnet wire) over sharp edges, the insulation can get nicked and short the coil out very easily. Your photo shows just that.

 

The link and the circuit image provided by the OP are not related. I guess the link has been updated.

Anyway, in general, the choice of whether to choose a ceramic or film type capacitor will depend on the quality of the signal and the working frequency. Capacitors of high voltage valve may have a high leakage (comparatively), so might effect performance.

The inductor coil may induce a high voltage, but seems to be confined, so no significant voltage increase.

 

Enamel insulated copper wire. I measured the resistance of the coil, i.e, 6.7ohms.
There is no short circuit as I checked the continuity with multimeter's continuity function.
Another thing that I tried today - I connected the coil to a scientec analog development board(breadboard). and increased dc input voltage up to 12V(no idea how much current the board was supplying). Coil got heated but some annoying sound was generated by the board so I removed the coil immediately. Also, I checked magnetic field with my Nexus 4 magnetic sensor using some apps and I got the positive result.ie, magnetic field was generated. So, I think it's the low battery current which causing the problem. Is it good idea of powering the circuit with cell-phone charger or using a rectifying step down transformer?

 

Is it good idea of powering the circuit with cell-phone charger or using a rectifying step down transformer?

Cell phone chargers are switching type power supply. The inbuit filters are not that good. There will be higher order harmonics in the power rail and could effect a circuit that is sensitive to high frequencies. Better go for a transformer based power supply.

This is one of the reasons audio setups prefer transformer based PS unless specially designed filters are incorporated.

 

You really think that this device induces sleep?
I misunderstood ?

If you have results, write to us please.

 

@Motanache
I didn't design that circuit. I'm just trying it. If I got some results, I'm surely going to post. Afterall so many people are helping me.

 

Cell phone chargers are switching type power supply. The inbuit filters are not that good. There will be higher order harmonics in the power rail and could effect a circuit that is sensitive to high frequencies. Better go for a transformer based power supply.

This is one of the reasons audio setups prefer transformer based PS unless specially designed filters are incorporated.

Not to be picky, but...
1. Cell phone chargers *are* transformer based.
2. The input filter has no affect on high-order harmonic noise on the DC output. The input filter is there to keep switching noise from going back out the AC input connection and radiating interference into the surrounding area. True, it will attenuate some incoming noise, but most of the noise on a switching power supply output comes from the power supply circuit itself.

ak

 

1. Cell phone chargers *are* transformer based.

Agree in the context of isolation. I meant to say that the frequency involved in the cell phone charger is greater than 50Hz or 60 Hz. Hence the switching frequency could effect the performance of the circuit the OP is interested in making.

 

OK - 18 posts and no link to the original circuit and no BOM, so basically a useless thread. Try this:

http://www.redcircuits.com/Page48.htm

This is the original circuit with a BOM. Note that the two CMOS oscillators both run at fewer than 10 Hz and have multi-megohm feedback resistors. This means that they would be more susceptible to spark-plug ignition noise from Mars than anything coming in from the power line. Except for the two timing caps, which are large enough to drive the time constants up into seconds and ignore all extra-terrestrial interference.

Basically, this is a pseudo-random pulse generator based on two non-synchronized oscillators driving two almost-identical pulse formers into an output driver. Personally, I would delete D4 and replace D5 with a Zener so the output could ring a little. An exponentially-damped sinusoid is a much more effective energy coupler, plus it has one of the magic words in the name.

Good morning, everyone.

ak