I've never used MOSFET in any application until recently. I don't completely understand how the Mosfet can be activated
The application I've worked on is when button is push, it powers the 555 timer and turn on an LCD for a specific amount of time. After X time, it cuts down the power to the timer and the LCD to save battery. What I use are a push button, two N mosfet (from radio shack) and 555 CMOS timer.
My set up:
The push button (the type that you push, it's connected. You release, it's disconnected)
Button connects to the Gate of 1st mosfet, Source to GND, Drain to Gate of 2nd N mosfet.
Source of 2nd mosfet to GND, Drain of 2nd mosfet to Pin 8 and 4 of the timer and to (+) of LCD.
Pin 3 of timer to Gate of 2nd mosfet
The rest of the 555 timer is setting up as Astable mode. The 555 timer supposes to turn the LCD on for 40 sec and shut down all the power to save battery.
My question is:
1) Did I set up the mosfet correctly?
2) When I try to measure the output current of the timer, I couldn't. The multimeter shows 0. What would be the correct way to measures output current of the timer?
3) When I push the button, measure the Drain-GND voltage of 1st mosfet, there's nothing
Any help would be greatly appreciated.
Thank you
The application I've worked on is when button is push, it powers the 555 timer and turn on an LCD for a specific amount of time. After X time, it cuts down the power to the timer and the LCD to save battery. What I use are a push button, two N mosfet (from radio shack) and 555 CMOS timer.
My set up:
The push button (the type that you push, it's connected. You release, it's disconnected)
Button connects to the Gate of 1st mosfet, Source to GND, Drain to Gate of 2nd N mosfet.
Source of 2nd mosfet to GND, Drain of 2nd mosfet to Pin 8 and 4 of the timer and to (+) of LCD.
Pin 3 of timer to Gate of 2nd mosfet
The rest of the 555 timer is setting up as Astable mode. The 555 timer supposes to turn the LCD on for 40 sec and shut down all the power to save battery.
My question is:
1) Did I set up the mosfet correctly?
2) When I try to measure the output current of the timer, I couldn't. The multimeter shows 0. What would be the correct way to measures output current of the timer?
3) When I push the button, measure the Drain-GND voltage of 1st mosfet, there's nothing
Any help would be greatly appreciated.
Thank you