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Timer and Counter Modules - del90002


U1 CD4541 is a Timer with Long Duration Ability. This timer is started by a low pulse from earlier circuit, when the temperature goes above setpoint, a low state is at U2A inputs, this starts the timer. The timer output goes high after a preset time. U2C-D Flip flop is power on reset via cap C7. Even a manual 'reset' is used if required. This alarm toggle is 'set'  when The temperature remains high even after the preset time period of U1.  

Look no code - How counters and timers were built with traditional cmos logic chips - Up-Down counter-timer

The 74C926 is used here as a four digit counter, The transitions of temperature from earlier circuit, that is the number of times the Process value goes above the Setpoint is recorded in this. A Display switch is given to save power. A reset pushbutton can bring the counter to zero.

Learn how the Frequency Divider 74HCT4040 works. Get a long duration pulse width. Best Pulse Stretching!

A digital counter monitors the number of times a process goes beyond a certain temperature limit over a long cycle of time. This circuit has a Analog Timer and Digital Counter. The Analog timer turns on an Alarm if the Temperature Limit transition is very long.

To view the circuit below, Click the Link of PNG or PDF and view the Circuit, PNG can be Scrolled with  Drag-Drop Left-Click-Mouse and you could use the PDF to take a paper print for reference only.

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Timer and Counter Modules - del90002
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Timer and Counter
                        Modules - del90002

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Learn more about the chips used in this circuit and others who have built similar solutions in varied applications.

Accurate Electronic Stop-Watch
Here is a simple circuit which can be used as an accurate stop-watch to count up to 100 seconds with a resolution of 0.01 second or up to 1000 seconds with a resolution of 0.1 second.

40MHz Frequency Counter Module
Here is the design for a very low cost 6-digit frequency counter module using of the shelf components (and not that expensive 74C926!).

Fairchild 74C926
These counters consist  of a 4-digit counter, an internal output latch, NPN output  sourcing drivers for a 7-segment display, and an internal  multiplexing circuitry with four multiplexing outputs.- Fairchild Semiconductor.

Long Duration Relay, up to 20 hours
4020/4040 chip -This chip and the 3-step rotary switch, can provide a maximum division ratio of 81,920 making it possible to time for periods up to 20 hours or so.