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Hi, FvM! Thank you for ur trouble.
My Pic schematic circuit is as follow.
And my relay drive circuit & power circuit as follows.
Externally IR sensor signal entered to RB7.
According to th signal , Relay1, Relay2 converted(0, 5v).
Hi, All!
I found new thing.
I exchange th motor direction switching.
Originally according to th IR signal, motor direction decided.
PIC16f877a RB7 is sensor input & I use PORTB interruption over change, RB2, RB3 is motor drive output.
I input th 0, 5v signal manufactually instead of IR...
Accoding to ur opinion, I exchanged th PIC and BSS138, 7805.
But with motor, 7812 and 7805 overheated.
My 12v,5v power supply circuit as follows.
After removing power , I check power element then 7812's 10 ohm resistor burnt and its value is 0 ohm.
What do u think that about back EMF of motor...
My reference board is using 24v,3A power switching circuit and 12v by 7812, 5v by 7805.
At first I havent power ,so I use reference boards power.
But unfortunately I unprovide th power Vdd, only provide 5v power to Vref pin.
Then Pic outpin dropped 2.5v, 7805 and 7812 overheated.
After that I...
According to ur opinion, I connect 24v power supply and 12v,5v power supply separately externally.
At first I common their ground, then 12v and 5v power supply dont drop but PICs output pin stoped.
I check it by connect led.
So I separated their ground i.e 24v, 12v, 5v, then my project works...
Hi, FvM. U mean tht my switching power is unsufficent to provide current required to drive motor?
As a matter of fact I refer to the sample board.
In Sample board, motor works well by switching power.
I design my project as the same sample , but my board sometimes works well, but a few seconds...
Hi amayilsamy!
My relay coil resistance is 400 ohm.
Relay coil drive voltage is 12v, so current is 30mA.
So I think Mosfet is full to drive relay coil.
Hi All! Im beginner @ circuit field.
I hav a problem with control dc 24v motor by pic16f877a.
My circuit is as follows.
Pic16f877a output pin drive mosfet bss138 & bss138 drive relay coil.
Pic control dc motors rotate direction according to IR sensor signal.
Im using 24v switching power by...
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