How can you build an electronic controlled timer for a deer feeder?

Answer 1

The easiest approach is to use a 555 timer. See the related links to learn all about the 555. Then build one of their circuits, and adjust the two resistor values (connected to pins 6 and 7, and then 7 to 8.) and adjust the capacitor until you get the timing you want. The ratio of the resistor values is the ratio the output will be high then low. This is called the "Duty Cycle". In your case, you want to generally have a 9:1 ratio, because you want to detect when a certain amount of time has passed. So one resistor value must be 9 times the other one. To calculate the approximate waiting time, just take the larger resistor value and multiply it by the capacitor value. To calculate the approximate "active time", take the lower resistor value and multiply it by the capacitor value. "active time" occurs when the desired amount of time is over. This "active time" period lasts for a short while then the process starts all over again. To sum up, Experimenting with the 555 timer is your best answer. It depends on the resources available and the extent of control desired, acceptable cost, whether or not solar panels or other power sources are available, etc. Option 1. Analog approach, based on timer ICs such as the venerable 555. Advantages: simple circuits. Disadvantages: long delay times between feedings require expensive components for acceptable accuracy, temperature swings can drastically affect timing. Option 2. Analog approach with sensors, using a light sensor to detect dawn/dusk and one-shots to time feed dispensing. Advantages: more appropriate operation times. Disadvantages: circuit complexity and sensor placement, possibility of false triggers (clouds, trees, or animals affecting sensors). Option 3. Analog plus digital approach, based on a timer IC or crystal oscillator and digital dividers. Advantages: better timer accuracy. Disadvantages: circuit complexity. Option 4. All-digital approach, based on microcontroller with crystal oscillator. Advantages: better timer accuracy, fully programmable feeding times and dispensing. Disadvantages: circuit complexity, programming required. Option 5. CPU approach, based on industrial computer with cellular modem interface, possibly with camera(s). Advantages: remotely user-controlled, monitorable. Disadvantages: circuit complexity, power requirements, geekiness. By all means use the lm555 timer plenty of design ideas on the internet The only variation i will add to the timer is a trigger where by it will begin timing as the deer approach the feeder. The time for the feed can then set by you as desired time. just one lm555 will do it. or install a computer camera and what not to replace it. If you listen to these fellows first thing you know you are using a $300 a computer power supplies and what not. The sign of a good engineer is the guy that solve problems as efficiently as possible. A $ 5.00 ac mechanical timer good for 24 hour provide ac output to an electrical device to open or close a flap. run an ac motor your choice.