Hot answers tagged

7 votes

Paralleling two MOSFET Solid State Relays

Gate resistors do not apply at all. It does not apply because you do not have direct access to the MOSFET gate in an opto (or an SSR). You're driving an LED, not the MOSFET gate. That said, LEDs still ...
user avatar
  • 46k
5 votes

Paralleling two MOSFET Solid State Relays

This works fine. You put the LEDs in series and the output switches in parallel. That also means that you control them as if it were a single switch eventually.
user avatar
  • 10.2k
3 votes

Paralleling two MOSFET Solid State Relays

Can I drive both devices through the one gate-drive resistor? If you mean opto driven gates, YES, by putting the LEDS in series and reducing the R value for the remaining R voltage drop and desired ...
user avatar
3 votes
Accepted

How to prevent LED strip from flashing at full brightness when the ESP32 boots

According to Adafruit documentation, the pin "A0" is pulled up with 10k resistor onboard the PCB. According to Adaruit documentation, they don't seem to even know why ESP32 documentation ...
user avatar
  • 87k
1 vote

Using the WS2811 as a vibration motor control

The current the WS2811 sinks is around 16.5mA (15.5mA minimum). PWM frequency is said to be > 2kHz. Probably there is only a sink, no pull-up. Try this: simulate this circuit – Schematic ...
user avatar
1 vote
Accepted

Formula to calc Id of this IRF3205 in the linear region from this specific voltage measure point

The current in each MOSFET is the voltage across the source resistor divided by the value of the resistor. It is assumed that the gate current is negligible. In the schematic shown the source resistor ...
user avatar
1 vote

How to prevent LED strip from flashing at full brightness when the ESP32 boots

The pins are likely initialized to a floating, high impedance state. A floating MOSFET gate can pick up charge and spontaneously "turn on." A pull-down resistor on the gate would prevent ...
user avatar
1 vote

How to switch a SIM800L modem on/off with an ESP32-CAM, without a relay?

The 3.3V from the module is not enough to turn on the IRF530, which has a threshold voltage of 2-4V. 5V should be enough, which gives you options. You could change the IRF530 for another device (BJT,...
user avatar
  • 6,530
1 vote

Bulletproof H-Bridge

I've been thinking about a couple of approaches to doing this. The cognoscenti seem to go with stepping up the DC to a high voltage (165V for 120V/60Hz, or 330V for 230V), then using a high-voltage ...
user avatar
  • 40.2k
1 vote

Bulletproof H-Bridge

You need to ensure you have non-overlap on the HS and LS FETs in the H-Bridge. With an inductive load, you also need to ensure you have sufficient V rating for your FETs, and also that the VCC and GND ...
user avatar
  • 12.4k

Only top scored, non community-wiki answers of a minimum length are eligible