- Wed Mar 16, 2016 4:32 am
#43279
Hi, the ILD74 works a treat. If your using it with the EPS8266-01 the LED side can be connected between Vcc and GPIO 0 / 2 so that it doesnt mess with booting, you'll need to invert the output in your code though.
- Wed Mar 16, 2016 6:42 am
#43291
I have one of those too but it has a 60ma forward current. I must be confused about something. I find that the esp can source 12ma and sink about 20ma: http://bbs.espressif.com/viewtopic.php?t=139
All of the options I have on the table as of now use more than 20ma. I tested my ILD74 with a 150ohm resistor on 3.3v and it still had over 100 ohms resistance on the collector/emitter. I don't recall current draw but should be 22ma.
All of the options I have on the table as of now use more than 20ma. I tested my ILD74 with a 150ohm resistor on 3.3v and it still had over 100 ohms resistance on the collector/emitter. I don't recall current draw but should be 22ma.
- Wed Mar 16, 2016 7:10 am
#43293
3.3V - 1.4V(diode forward volt drop) = 1.9V / 150 ohms = 12.6 mA. I never had a problem with the ILD74 not switching fully, it might be worth testing with a load and checking the volt drop accross it.
Trent wrote:All of the options I have on the table as of now use more than 20ma. I tested my ILD74 with a 150ohm resistor on 3.3v and it still had over 100 ohms resistance on the collector/emitter. I don't recall current draw but should be 22ma.
3.3V - 1.4V(diode forward volt drop) = 1.9V / 150 ohms = 12.6 mA. I never had a problem with the ILD74 not switching fully, it might be worth testing with a load and checking the volt drop accross it.
- Wed Mar 16, 2016 9:52 am
#43308
@Trent Can you measure the value of the resistor in series with the LED side of the optoisolator associated with one of the relays without power? Apply 3v3 to Vcc, ground the input pin to energize the relay and then measure the drop across the resistor.
