All Questions
28 questions
0
votes
1
answer
39
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Using MOSFETs to control series-wound flipper coil
I'm trying to control a series-wound pinball flipper coil using two N-Channel MOSFETs, like this:
The switches are mechanical leaf switches. The diode D1 is part of the coil assembly, I don't know ...
- 101
0
votes
2
answers
57
views
Not getting spark from ignition coil test circuit
I have a simple circuit setup with an N channel MOSFET switching ground to a two pin ignition coil. I am not getting any spark from the spark plug in the coil. Could someone take a look at the ...
0
votes
2
answers
128
views
Best method to dampen inductive spiking from pulsing coil with MOSFET?
A simple diode works across the coil to lower the voltage spikes, but I ideally need a way to absorb the inductive spiking as fast as possible. I've heard a Zener diode across the drain and source of ...
0
votes
2
answers
110
views
Best way to generate a variable clean DC current
On one end I have an amArduino or other microcontroller. On the other end I have a small electromagnet coil with about 20 turns of 1 inch diameter. I need to drive this coil with some precision (say 5-...
- 207
0
votes
1
answer
102
views
Should I use an N-channel or a P-channel MOSFET in a coil gun?
With an N-channel MOSFET, the coil is located between Vcc and drain so when the MOSFET switches off the coil has to create a big voltage spike because it has to overcome the MOSFET.
Is that problem ...
2
votes
2
answers
289
views
Boost Converter 9v to 450v as Capacitor Charger
I recently decided to build a simple single-stage coilgun that is triggered by a SCR. For that, I had to design a low-power boost converter that only draws around 2 W at 9 V so I can power it from a 9 ...
- 23
1
vote
1
answer
66
views
Should I disable this IC for this case?
Screenshots:
imgur.com
I need to apply up to 4.2 V to a 1.1-1.7 Ω coil. I want to apply this voltage only when COIL_ACTV is HIGH. COIL_ACTV is the output of a GPIO pin (3.3 V). To control this, I am ...
0
votes
1
answer
227
views
Why is the MOSFET in my circuit getting very hot?
I want to drive the inductive coil (26 ohm) at 48V DC. I have a 4N65 N_MOSFET. I'm giving 9V Vgs @ 150Hz switching square signal. For spike protection I used TVS diode having part number 3.0SMCJ170A.
...
- 303
1
vote
2
answers
378
views
What's causing MOSFET driver failure in my coilgun circuit?
I'm working on a small coilgun, and am running into an extremely annoying problem with my circuit.
Circuit schematic:
PCB Layout:
Key components:
Flyback diode: BYC30X-600PSQ
Flyback resistor: ...
- 39
2
votes
3
answers
3k
views
Driving Ignition Coil with Microcontroller
I am trying to design a circuit to drive an ignition coil in an automotive application using a microcontroller. The microcontroller operates on a 5VDC input and puts out a 3.3V and 4mA digital signal ...
- 53
2
votes
2
answers
573
views
How to switch a 700A 200V pulse for a coilgun?
I'm working on a coilgun and I need to discharge a capacitor bank through a coil to create a strong magnetic field. My coil has a resistance of 266 milliohms and when fully charged, the capacitors are ...
- 21
1
vote
0
answers
211
views
Why coil at high frequency pass lower current?
I am currently working on a project that uses an H-bridge to output different direction current.
I use 2 P-channel MOSFETs (IRF4905), and 2 N-channel MOSFETs (IRF3710) to build my H-bridge.
*reference ...
- 11
1
vote
0
answers
993
views
Mosfet driverless mosfet Slayer exciter (adjustable power)
I'm new to electronics but I tried to make mosfet slayer exciter anyways. Most of the mosfet slayer exciter I've seen uses mosfet driver to turn on the gate of the mosfet, but since I don't have ...
1
vote
1
answer
1k
views
Power a coil with a MOSFET driven by a BJT in ground
I am trying to do something something maybe trivial. I have little to no knowledge in transistors so bear with me.
I want to power a high voltage coil with a low current switch using transistors I ...
- 13
0
votes
0
answers
193
views
DC boost converter output voltage problem when load is connected
I have successfully finished one part of the DC converter. Now I came across a certain problem which I can't solve myself.
When I didn't connect a load to the output of the dc converter, there was ...
- 19
-1
votes
1
answer
709
views
Does the lack of a primary DC blocking capacitor cause my tesla coil driver to explode?
Lately I've been tinkering with an SSTC half-bridge driver. I've ran a couple of tests using relatively low input voltages ~50V and the IGBTS seemed to do fine, there was no noticeable heating at all. ...
- 13
1
vote
2
answers
2k
views
Replace DPDT relay with Mosfet?
Currently I have this UPS power setup for my Router with the help of a DPDT relay so that the router works when mains power supply fails. The working principle of my project is real simple. Two ...
- 712
0
votes
2
answers
1k
views
Selecting a MOSFET to drive a coil with a square wave
I need help with finding an alternative to the IRF1310 in the circuit shown. The circuit is going to be controlled with a microcontroller with 3.3 V logic.
The simulation of the circuit in LTspice ...
2
votes
1
answer
1k
views
Mosfet Gate Driver far from mosfet
I'm building a MOSFET+LiPo battery driven multi stage coilgun as a hobby.
My question is:
How much does MOSFET gate-> Driver circuit distance matter in my case?(very low frequency)
I've read many ...
- 145
-2
votes
3
answers
2k
views
Driving bipolar transistor with mosfet?
Is it a proper way to drive bipolar transistor with mosfet?
Or should I simply skip Q1 and drive coil directly with mosfet? (with extra diode to protect mosfet)
The point is that I have Q1 already ...
- 97
1
vote
1
answer
2k
views
Need help trying to design an H-Bridge to power electromagnet
I am trying to design an H-bridge inverter to supply maximum current to my coils. I need to supply as much current as possible so that I can make a electromagnet whose polarity constantly flips so ...
- 25
1
vote
1
answer
695
views
Will this phototransistor circuit work?
I'm building an 8 stage coil gun for a physics project, and I want to verify this circuit as I've never used a phototransistor before and I'm still pretty new to mosfets. Here is a schematic:
The ...
- 15
5
votes
2
answers
4k
views
Induction heater circuit problem
I am trying to build induction heater with the help of the following schematics(taken from this page):
So I am using 220:10Vrms(15Vpeak) transformer with fullbridge rectifier and a capacitor to get ...
- 1,226
0
votes
2
answers
554
views
how to control a coil
I have been working on a project controlling a coil to attract a metal ball at high speed.
I measure the speed of the ball in front of the coil and then decide how fast I want the ball to accelerate ...
0
votes
2
answers
473
views
Short-circuit primary side of a transformer to collect all the spikes at the secondary
Abruptly detaching a power source from a coil produces a back-emf: this is a well known fact.
What I would like to achieve, in my experimentation, is to convey ALL the collapsing magnetic field to ...
- 55
0
votes
2
answers
156
views
Best way to control heater coil in portable application
I have a resistance wire (kanthal) that is about 2 ohms; with a power source of 3.5V. I'm trying to figure out the most efficient and portable way to control the coil; I'm toying with a mosfet right ...
- 549
7
votes
2
answers
14k
views
Reduce noise from a Hall effect sensor
I am currently working on a magnetic levitation project using a Hall effect sensor for distance measurement. I drive the coil using two 12 V car batteries in series to form a 24 V DC source, ...
- 81
3
votes
2
answers
8k
views
Estimate current through inductor in DC circuit with PWM control
I am designing a circuit to control an electromagnet (coil with iron core) through a N-channel MOSFET driven by a PWM signal.
I can't figure out how to derive the relationship between the PWM duty ...
- 153