I agree that a 12V transformer would be a good place to start, considering our OP's inexperience. However, he never said anything about needing a relay.Indeed, on the brigde output to filter current. Electrolytic capacitor are excellent for that. Why don't you use a 12V transformer instead? You just need to use a 12V coil/relay, which is quite common.
The formula to calculate the capacitor's capacitance:
C = Il / (2 x Vdc x ripple_factor x Fm)
Il - Load current;
Vdc - DC voltage;
ripple_factor - Factor of ripple you want for your project (0.1 or 10% is enought for amplifiers, 0.05 or 5% should be considered for your project);
Fm - Mains frequency (50Hz in Europe, 60Hz in the US).
You will certainly overvoltage the 555 during the low current intervals. Better to use a transformer and totally exclude the voltage divider.
I assumed that the coil was from a relay. I had no hints from this thread to assume that. Sorry!I agree that a 12V transformer would be a good place to start, considering our OP's inexperience. However, he never said anything about needing a relay.
Whats an op?our OP's inexperience
Because of Ohm's Law and Kirchhoff's Laws. Did you read the link I provided?Why is that a problem?
Impedance is the perceived resistance of a component in a "alternating current" situation. In your case, the current is not an alternating current. Though, it varies with time (it is a pulsed current). If we are talking about pulses with apreciable intervals of 1s, then the coil's impedance won't be much different of it's DC resistance.But DC does not have impedance..?
do you mean the part before the diode bridge?
would it be inductive impedance or capacitive impedance?
I dont understand impedance very well. It seems really weird and does not make sense.
can you explain it?
No its not for a relay its kind of the primary of a air core transformer. The secondary is another air core coil.By the way, is this the coil of a relay?
1- ok i will fix thatYou need to make a few changes. Some are necessary, some are only suggested. I have circled them all.
1. Your bridge outputs were wired backwards.
2. You need a GND connection for your 555.
3. Five volts from a 555 will not turn your FET on reliably unless you have a logic level FET. I suggest you use a 12V regulator to solve this potential problem.
4. Unless your coil has lots of turns of fine wire, you will probably smoke your FET. I would add a current-limiting resistor, at least in the beginning. You can always short it out later and see if your FET survives.
You don't need to connect anything to earth GND. You did not have a common connection between your 555 and the source of the FET. Look at your previous schematic.No its not for a relay its kind of the primary of a air core transformer. The secondary is another air core coil.
watch this video http://web.media.mit.edu/~xercyn/sight/levitation/resSmaller.mov
Read Wireless Power Transfer with a Tuned Resonant Air-Core Transformer:
1- ok i will fix that
2- GND ? where would that be? isn't it enough to connect it to negative?
You can. See below.3- ok i will use a 12v regulater. Can i use the 5v regulator to output 12v?
Sure, especially if you don't have a heatsink. Do you have a part number for your FET? A thousand pardons if you already posted it.4- I have a 45 watt fet will that also burn?
Oh! wow i totally missed that!You don't need to connect anything to earth GND. You did not have a common connection between your 555 and the source of the FET. Look at your previous schematic.
Your schematic is still screwed up. Don't quit your day job.Ok here are the changes.
Also Can i add a current increasing transistor to send more current to the coil?
School IS your day job. Don't quit! (I'm not implying you were thinking of it.)Day job -.- ... mumble.... i got to go to school...
I thought I fixed the diode bridge.
I didn't mean to switch it to a 2n7002 it was by electronics workbench.
No its not running. I first want to draw a circuit then I will build it.
Thanks for the corrections Ron!
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