ELM307

ELM307 Camera Control Description The ELM307 is a retriggerable one-shot circuit that has been designed for electronically controlling the shutter of a film or digital still camera. The circuit provides a variable pulse width timer, a variable delay reset timer, power control, and an LED status drive all in an 8 pin package. In operation, a monitored signal (alarm contact, audio signal, oscillator signal, etc.) is applied to the circuit’s Trigger input. A low level at this input immediately causes an output at the Camera pin (controlling the shutter) that lasts for the duration set by PW. Further triggering is inhibited until an additional period (set by Delay) passes, allowing time for the film to advance or for the digital image to be stored. To help with setup, the circuit has a test mode in which the Camera output is blocked, and the LED is instead energized. Toggling between the test mode and the run mode is accomplished with the single pushbutton input, as is the power on and off. Applications Security camera control Candid shots of animals or people Time lapse photography Remote triggering of cameras Features Low power CMOS design - typically 1mA at 5V No external timing elements required Test mode assists with setup Single pushbutton control Auto power off saves batteries LED output shows status High current drive outputs - up to 25mA Connection Diagram PDIP and SOIC (top view) VDD 1 Delay 2 PW 3 PB 4 8 VSS 7 Camera 6 LED 5 Trigger Block Di...