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
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
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
Counter Modules - del90002
is a Preview Image Linked to the Larger Circuit
More Related Reading :
Learn more about the chips used in this circuit
and others who have built similar solutions in
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.
Here is the design for a very low cost 6-digit
frequency counter module using of the shelf
components (and not that expensive 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
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.