1. K

    Driving a GPO Telephone bell with MOSFET

    I have a vintage GPO telephone. The bell inside is circa 70V a.c. It comprises two coils (centre tapped) - effectively 2 x 35V coils. Which I want to drive with a DC pulse. I took the centre-tap as 0V and connected the two coils (with flyback diodes) to MOSFET based modules (FR120N) which are...
  2. V

    How to detect receiver (smartphone) with a wireless charger transmitter (base)?

    My end goal is to build a circuit with a wireless charger transmitter module and a led indicator that turns on when the receiver is detected and wireless charging is occurring. I’ve been reading about the analog pings the TX uses to detect RX, Foreign Object Detection (FOD), Q-factor...
  3. Marcodavid

    Solenoid Flyback protection

    I am planning to make solenoid: *Coil = 3.5 Ohm Dc - 3.5 mh inductance *Capacitor = 450v- 1000 uf *Dc Battery = 12v *Dc Booster = up to 400v *Push button switch Iam willing to operate it on 150v or 200v I am worrying about the switch to get damage by the back emf I did some research...
  4. F

    Online Coil Inductance Calculators yeild different Results

    Subject: Online Coil Inductance Calculators yeild different Results Designing an open air coil wound on PVC pipe with the following specs ... Wire = 12 gauged insulated electrical wire from Lowes - Wire Diameter = .125 including the insulation - Turns per inch = 8 - Total Turns = 212 - Coil...
  5. Marcodavid

    design an RC snubber for ac solenoid lock ( inductive load)

    I am designning ac solenoid lock, read the inductive load needs snubber circuit to protect from inductive turnoff transients Here is my design Resistance 8 ohm Main outlet power source 220 - 50 hz Inductance 150 mh Impedance 47 ohm I (rms) ~ 5A So do i really snubber circuit? If so iam...
  6. C

    What is the function of high current induction heater circuit elements?

    Note: English translation is below. Herkese merhaba, Bu devrede komponentin görevleri nelerdir? Örneğin: - Dirençler ne işe yarar? - Bu devrede diyotlar ne işe yarar? - Toroid sargılarının sayısı artarsa ne olur? - Birden fazla kondansatör paralel bağlanırsa ne olur? - Devrenin verimli...
  7. A

    Making electromagnet and not burn the Magnet

    Hi All, I have made an electromagnet of using 1 mm diameter wire appx 60 turns. here is the problem... i have 600W smps(computer power supply) and i want to use that to power my electromagnet. On smps it shows 3.3V with 25A and 5V with 18A. If i connect my electromagnet to one of these terminals...
  8. TiredGradStudent

    First PCB Build Problems (I2C Driven Motor Driver Board): DRV8872 Motor Driver

    Hello All, I am developing a very small I2C controlled Motor Driver PCB Board for a robot for my master's thesis. The idea is simple: Use ATTINY816 to send two PWM signals to the DRV8872 Motor driver to actuate an electromagnetic coil back and forth between two magnets. The PWM signals switch...
  9. J

    Axial flux motor with single coil

    Disclaimer: I am not an expert, only enthusiast. Hi, i want to experiment with a small scale axial flux motor and a single coil. The first question is what should be the polarity of the magnets? Same or alternating? The second question is what should be the shape of the coil. Is a core needed...
  10. D

    Defining DFLOP output

    Hello, I would like to know how do I configure the DFLOP with + -15 V or whatever other voltage. I tried several things but it still has + -1V.
  11. B

    Startups increasing efficiency in motors. Revolutionary ideas or old ideas dressed up with marketing?

    I was looking into companies or startups that were doing things with motors to improve efficiency. I stumbled upon Turntide Technologies, which has a partnership with Amazon. Turntide is making a software-driven motor that "enables precise and reliable control to effectively use every watt of...