I am making a long-term time-lapse camera controller, using as little power as possible--it needs to work on battery power for months.
I have the 14M2 sleeping until a real-time clock (DS3231) sends an alarm output to one of the 14M2's input pins. The 14M2 wakes up and using one of its pins switches on a mechanical latching relay. This provides power (11.1 V stepped down to 8.5 V) to the camera, which then turns on by itself. The camera is powered on for one minute to charge its internal supercapacitor (a coin "battery" which holds the date and settings and usually is charged with the camera's removable battery, which is not used in this setup). Then using a second pin and an opto-coupler (I read that this is better than a transistor since the two power systems are more isolated), the camera's remote shutter circuit is closed so an image is taken. The camera power is held on for another minute and then shut off. Then the 14M2 writes the new alarm time to the RTC. Then it goes back to sleep.
I see that the 14M2 project board kit I have (the AXE117) has an optional Darlington driver buffer chip that "enables you to connect higher power output devices (such as motors, solenoids, relays) directly to the board (current up to 500mA)". I am way out of my familiar territory here, but I am wondering whether I can use the Darlington driver buffer chip in place of the latching relay and if so, what would be the current draw through the AXE117 while the switch is held closed?
I have the 14M2 sleeping until a real-time clock (DS3231) sends an alarm output to one of the 14M2's input pins. The 14M2 wakes up and using one of its pins switches on a mechanical latching relay. This provides power (11.1 V stepped down to 8.5 V) to the camera, which then turns on by itself. The camera is powered on for one minute to charge its internal supercapacitor (a coin "battery" which holds the date and settings and usually is charged with the camera's removable battery, which is not used in this setup). Then using a second pin and an opto-coupler (I read that this is better than a transistor since the two power systems are more isolated), the camera's remote shutter circuit is closed so an image is taken. The camera power is held on for another minute and then shut off. Then the 14M2 writes the new alarm time to the RTC. Then it goes back to sleep.
I see that the 14M2 project board kit I have (the AXE117) has an optional Darlington driver buffer chip that "enables you to connect higher power output devices (such as motors, solenoids, relays) directly to the board (current up to 500mA)". I am way out of my familiar territory here, but I am wondering whether I can use the Darlington driver buffer chip in place of the latching relay and if so, what would be the current draw through the AXE117 while the switch is held closed?
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