Hellooo everyone! I'm first time here.
I got a problem in MOSFET, hope to have some advice & guidance.
Please refer to the attached schematic(zip file), Im using a IC (555 timer) pin 6 signal & an Op amp (LM358) to produce PWM signal hence to control the brightness of strings of 1W white(color) LEDs, through a MOSFET (BUZ11), the components are mounted on breadboard, except the LEDs & its branch resistors are soldered on Vero board.
Im expecting total 1.7A of current flow thru the entire branch of LEDs (0.34A per branch x 5 branches), however only 0.16A of total current flowing thru, at 100% duty cycle.
So far Ive tried using MOSFET IRF510 & IRF540, could not get the expected current, & the frequencies generated by 555 timer tried are 140 kHz; 100 kHz; 10 kHz 5.2 kHz.; & now 200Hz I attached a snap shot of waveform signals at pin 6 of 555 timer & at MOSFET gate, oscilloscope sweep time/div: 1msec, volt/div: 2V. The total branch current measured was 0.08A at this instant.
Thank you for your time.
I got a problem in MOSFET, hope to have some advice & guidance.
Please refer to the attached schematic(zip file), Im using a IC (555 timer) pin 6 signal & an Op amp (LM358) to produce PWM signal hence to control the brightness of strings of 1W white(color) LEDs, through a MOSFET (BUZ11), the components are mounted on breadboard, except the LEDs & its branch resistors are soldered on Vero board.
Im expecting total 1.7A of current flow thru the entire branch of LEDs (0.34A per branch x 5 branches), however only 0.16A of total current flowing thru, at 100% duty cycle.
So far Ive tried using MOSFET IRF510 & IRF540, could not get the expected current, & the frequencies generated by 555 timer tried are 140 kHz; 100 kHz; 10 kHz 5.2 kHz.; & now 200Hz I attached a snap shot of waveform signals at pin 6 of 555 timer & at MOSFET gate, oscilloscope sweep time/div: 1msec, volt/div: 2V. The total branch current measured was 0.08A at this instant.
Thank you for your time.
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