|
|
- CIRCUIT FORMS DIVIDE BY 1.5 COUNTER
Two inexpensive ICs divide a TTL clock signal by 1.5. By following the circuit with another flip/flop, you could also generate a divide by three function.
|
- DARKROOM CAMERA SHUTTER TIMER
This circuit was designed to control a film exposure shutter for a darkroom. It has 8 time steps ranging from 0.35 seconds to 4 seconds. It is activated by a foot switch and draws power from an external 12 volt DC supply.
|
- HONEYBEE COUNTER
I designed a circuit similar to this one a long time ago to help a beekeeper count the number of bees going into or out of a hive. The low power circuit uses a slotted opto-sensor to detect the passing bees. The circuit advances an electronic counting module whenever a
honeybee passes through the sensor. The device only counts the number of bees going through the sensor. A different circuit would be needed to count the number of bees only going out or only coming into the hive.
|
- LONG PERIOD COMPUTER WATCH DOG TIMER
This circuit uses a simple 4060 IC oscillator/timer which is reset periodically by a computer. Should the computer fail to send a pulse, the output changes state. The time can easily be set from seconds to hours.
|
- On/Off Flip/flop Circuit with Automatic Timeout
This circuit is ideal when a device needs to be turned on and off with a single pushbutton switch, but also needs to turn itself off after some period of time. With the components shown, the output will stay on for only about 20 seconds.
|
- Poor Man’s Digital Counter Using Pedometer
There are many occasions when you may want to count something electronically. Perhaps it is car traffic on a street or items moving down an assembly line. It might be the number of times a machine is
activated or maybe you want to count the number of people entering doorway. Commercial counting modules do exist but if you want to use something cheaper, you can modify a pedometer to do much the same thing....
|
- Poor Man's Timer
Often during testing of certain equipment and components, you would like to keep track of the elapsed time in hours, minutes and seconds. There are some nice commercial digital timers and counters available for just this sort of application. However, although it may not
be as accurate, there is a cheaper way to go. I’m sure many of you have some old wrist watches or battery powered dial faced alarm clocks collecting dust in some drawer.
|
