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Is there a way that I can still use the 0.1ohm resistor without changing it to 1ohm? And yes, I have connected the necessary load. first is to make 20mA and the other is 30mA just to know is there any increase in the voltage. I am using 5V rite now, so maybe the maximum limit is 3V like you've...
I took it directly from the circuit but it doesn't work. The output just shows my Vin. Got any idea how to test this to work?
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Is there any big difference if I took out the transistor? I used 2N3904 for this...
Oh yeahh~ Never know this datasheet before. I see it got a current sensing design there~ Thanks KJ6EAD
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Thanks IanP, I'll try to look at KJ6EAD and yours. Will tell the updates later yea
Hi and good day all,
I wanted to measure current from a motor. I measured that at normal operation the motor takes about 40mA. I am using a current sense resistor of 0.1ohm. Usually I use a HCPL-7520, but this time around I am trying to use a LM324 to solve the problem.
With a HCPL-7520 it is...
I got 11kV on a switchgear then to 110V using potential transformer, and then 5V using a transducer. This is for voltage measurement.
For current, I got 800-1000A from the switchgear and then step it down using current transformer 800/1A. Then using a transducer I got about 14-20mA. Current...
Last time I tried to do it like that, and it works, but without the opto of course. Hehe. Anyways, I think I just try putting a voltage divider, try to make it to acceptable to say 10V and ratio it to got like 5V in the PIC (which the ADC pins can have a maximum of 5V). So if it is 10V in...
Keith, it is 5V
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The opto that is intended to be used before the ADC at the microcontroller. Just wanted to protect the PIC from voltage spikes
I see. But I think it would be complicated as I would need 8 555 timer and 8 4n35 for my project. I think I will just let the ADC port get the signals directly from the contacts. It's just a prototype. The reason I wanted to put optoisolators because the project will interface with a 11kV...
Hurm... I've thought so. At first I've wanted to use the isolated linear sensing, HCPL-7520. But it is quite expensive at 11usd per unit. I need to use 8 pieces lol. I guess there's no substitute for the hcpl-7520 eh? Is there any cheap optoisolator that you guys can recommend? Thanks...
How do I improvised it to be directly proportional, Keith? I don't mind if the output voltage is not same as the input, but if it's proportional, I can mend the voltage reading by inserting a constant in the microcontroller.
Hi all,
I've encountered a problem. I've tried to set the input current to the opto by using 5V and 600 ohm resistor, resulting less than 10mA input current. On the output side, I have put the voltage to 5V and resistor as 1k. It outputs fine, however, when I decrease the input voltage the...
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