EEVblog Electronics Community Forum
Electronics => Projects, Designs, and Technical Stuff => Topic started by: China NewBoy on November 08, 2019, 02:03:54 am
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i have made a switching-mode power and i want my Atmega16 read if my power work
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in the current scheme,i use the optocoupler pc817 which is connect to the PWM chip(ob2269)’s Vdd.
but, i meet some problems , when the PC817 is connected to the VCC,the PWM chip dont work at all,because its Vin stay at 4.7V (the typical work volt is 19V). if the PC817 is NOT connected, i found the PSU work.
i wonder what caused this problem.
Here ↓ is my scheme pdf and some printscreen pics
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The startup current is very low. Vdd must have no load on it to start.
Does the opto need to be driven from the primary side?
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The startup current is very low. Vdd must have no load on it to start.
Does the opto need to be driven from the primary side?
im considering put my opto on the secondary side ,
i will do some experiments on the breadboard to figure out if it can work on secondary side
here ↓ is my new plan
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The startup current is very low. Vdd must have no load on it to start.
Does the opto need to be driven from the primary side?
im considering put my opto on the secondary side ,
i will do some experiments on the breadboard to figure out if it can work on secondary side
here ↓ is my new plan
it can work on the secondary side now! ;D ;D ;D
but im still wondering ,why adding load to VDD could impact the volt of Vin?
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Before the power supply starts, the only available current is via the VIN pin.
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Before the power supply starts, the only available current is via the VIN pin.
im still wondering about why the VDD's LOAD can lead to the Vin's volt drop...maybe just becasue im still a newbie and i know nothing about the chip...
but thank you really.the problem is solved now.