| james | Saturday, 30th December 2006 10:13am - No.647 |
| would this circuit be suitable for a auto transformer or car coil? |
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| RMCybernetics | Saturday, 30th December 2006 4:23pm - No.648 |
It would provide an adequate signal, but a large transistor would be needed for switching the power.
You can see examples on the ignition coil driver page or the power pulse controller page. |
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| geneotype | Sunday, 16th September 2007 3:58pm - No.1718 |
| dear rmc i have made quite a few square wave circuits in my time but no have worked. my power supply is that of a car battery charger 12v . i have noticed that it oscilates a little as most chargers do. would this affect my square wave circuits indering their performance? please reply soon as im hanging off the end of my chair to know thank you, sincerly geneotype. |
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| RMCybernetics | Sunday, 16th September 2007 7:10pm - No.1721 |
| Yes it would. You need to use a proper DC supply or a battery. |
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| geneotype | Wednesday, 19th September 2007 1:08am - No.1737 |
| ohh thank goodness i thought that i was so bad at electronics that every time i tryed the same circuit it never worked now i know why thank you now i wish i had of tryed dc insead of building the same circuit over 26 times spending $200 for a $ 4 circuit thankyou |
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| genotype | Tuesday, 25th September 2007 11:41am - No.1751 |
| dear rmc is there a transistor other than the 2n3055 that would work in the self resonation circuit for a flyback? high speed switching and heavy current loadig. |
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| RMCybernetics | Tuesday, 25th September 2007 11:59am - No.1752 |
A similar rated one might be TIP142 100V 10A. A MOSFET type IRF740 400V 10A would also work
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| Ben | Wednesday, 31st October 2007 10:33am - No.2093 |
RMC, fantastic pages here and a huge amount of patience for people on a steep learning curve like me!
Could C1 be changed to a value that would allow an IRF740 to switch a LED for testing. i.e. so you can see it flicker?
Also, feel really stupid here, which way round do I mount C1 and how do I tell the + side of the cap?
Many thanks
ben |
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| RMCybernetics | Wednesday, 31st October 2007 1:59pm - No.2095 |
Most caps are non polarized (there is no specific + or -). One which have larger capacity tend to be polarized and the pins are clearly marked. Typically these are electrolytic or tantalum capacitors. The -ve leg of such a capacitor would connect to GND in this circuit.
Capacitors larger than 100nF will allow you to see the output if connected to an LED. |
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| Ben | Wednesday, 31st October 2007 9:00pm - No.2100 |
It worked well and flashed at approx 2hz. Without a cap, i just upped the resitance/s which I figured from a handy 555 timer program.
Thing is, when I connected it to my coil the 555 gave up.
I had connected a cap and resistor as a snubber across the coil. also a zener 5W 15volt from the irf740 mosfet to ground.
Do you know what went wrong?
Thanks again
Ben |
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| RMCybernetics | Thursday, 1st November 2007 12:15pm - No.2104 |
| This circuit will not drive any coils by its self. It only provides signal. Maybe you should look at the ignition coil driver. |
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| dave | Wednesday, 28th November 2007 10:26pm - No.2257 |
Could you help me with a few queries on the'Dead bug' signal generator;
> What is the 100R next to the output of this circuit?
> Does a 1k resistor refer to a 1000 ohm resistor (1 k ohm)?
> Can any potentiometer be used as a variable resistor, or are they different components?
> Does the 9v input come from the positive battery terminal? If so, where is the negative battery terminal connected to?
many thanks.
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| RMCybernetics | Thursday, 29th November 2007 11:18am - No.2264 |
The 100R refers to a 100 ohm resistor used to limit the current flowing from the signal output.
Yes 1k is 1000 ohms resistor.
Any potentiometer witht he same resistance value will work. The one used here is a linear type.
Yes 9V is +ve battery terminal. -ve terminal goes to GND |
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| dave | Friday, 30th November 2007 9:19am - No.2277 |
What Wattage resistor (I wan't aware resistors had watts. the ones i've found are either 2, 7, 10 watts) would be suitable for the 1k resistors of the 'dead bug' signal generator, the 100 ohm resistor of the 'dead bug', the 10k resistor of the driver cricuit, and the 100 ohm resistor of the driver circuit?
And once the 'dead bug' circuit is complete, how do the potentiometers operate? (what do they do, or what should I do to them).
cheers. |
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| RMCybernetics | Friday, 30th November 2007 9:35am - No.2278 |
| This value just refers to the amount of power it can handle. The power in this circuit is tiny so it does not matter what value you use. |
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| newbie | Friday, 18th January 2008 3:58am - No.2451 |
| how do you connect the potentiometer? |
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| RMCybernetics | Friday, 18th January 2008 2:26pm - No.2458 |
| If you have vertical mount minature presets, you can just pluc them into the IC socket. if not, you will need to add leads to the pins and insert them into the socket. |
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| Ryan | Monday, 28th July 2008 3:57pm - No.2950 |
| What if you want a sine wave with a constant amplitude over a varying frequency range like a sweep tone generator |
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| Frank | Tuesday, 19th August 2008 4:21am - No.3004 |
| I have tried many different circuits similar to this, I've success and the circuits have failed miserably. In this circuit, pin 4 is disconnected to the positive rail. Why? |
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| RMCybernetics | Tuesday, 19th August 2008 1:37pm - No.3007 |
| Becasue of lazyness I suppose :) Most versions of a 555 will work when the reset pin is left unconnected, but it is probably better if you connect it to V+ |
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The term 'dead bug' refers to the way that the finished circuit resembles
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