New answers tagged

0 votes

Opto-Coupler window detector with delay

One approach can be using an p-channel mosfet instead of BJT transistors. Common P-channel mosfets have higher tresholds than BJT's, so you can use a smaller sized capacitor for the treshold detection ...
Ferrybig's user avatar
  • 1,154
0 votes

Opto-Coupler window detector with delay

Maybe you could use a 16V zener diode as voltage comparator and RC for pulse duration. A 4k7 + shottky quick discharges the cap in case of short pulse so the cap will be ready soon for next pulse.
Michal Podmanický's user avatar
3 votes

Watching an open-collector input without disturbing it

Your "black magic box" must be drawing some current through R2 and the transistor base-emitter junction, turning the transistor on. You could try adding a diode between the black box and ...
GodJihyo's user avatar
  • 23.4k
0 votes

Op Amp for DC Voltage Measurement

Many optocouplers like IL300 has many tolerances and mismatch sources. Like temperature, lifetime (LED aging), produciton tolerances (between two PDs). Use better a resistor divider on the voltage ...
eeeing's user avatar
  • 11
0 votes

Drive two bidirectional MOSFET constellations with the same optocoupler?

Will I be able to send two different signals on the different pairs? Like a serial TX through 1_A <--> 1_B and RX through 2_A <--> 2_B? Absolutely not without massive corruption. If ...
Andy aka's user avatar
  • 457k
5 votes

Controlling a relay with a raspberry pi pin 3.3 V

The optoisolator is not doing much as shown since you've tied the grounds together. You could just drive the transistor base directly with something like a 240Ω resistor. You should also have a diode ...
Spehro Pefhany's user avatar
1 vote

MOC3021M + JST16A-600B TRIAC Circuit problem: Resistor blowing up

R4 and R6 are connected directly to L, so when you switch on the gate through the opto coupler, that voltage will be applied and many current will flow until next zero voltage cross. See modification ...
Bravale's user avatar
  • 1,577
2 votes

Building SPICE models of optocouplers

Each aspect of an IC, such as the 6N137, has to be considered to make a complete model. It helps to have some understanding of what tools are available within Spice and how to apply each of them to ...
periblepsis's user avatar
  • 9,055
1 vote

Building SPICE models of optocouplers

The same way you do with any datasheet when you have no model: make a model, reproduce the test circuits from the datasheet in simulation, adjust the model parameters until you get a match.
John Doty's user avatar
  • 4,389
1 vote

I have a AD9833 function generator which has the ability to change frequency from 1k to 1MHz but a fixed 0.6V output I want 1V to 10V pk to pk

You have an inverting amplifier in your design, with R16 = 3.9k . To get a gain above 1 you will need the feedback (optoresistor) value bigger than 3.9k. However, if you check the datasheet for NSL-...
Ale..chenski's user avatar
  • 40.7k

Top 50 recent answers are included