Incorporating a Digital Display counter on a LIGHT DARK SENSOR. HELP !!

Thread Starter

Giggabyte

Joined Sep 19, 2008
15



Hie guys i am working on a project to progress the above circuit by encooperating a 7 segment led display . Basically i have made the dark sensor turn on a relay once darkness falls. Once active, the relay pinout would supply 12v to an analogue delay circuit which will discharge after 5 seconds thereby turning on an LED. Literally i have built a 555 timer circuit which will also be triggered by the relay vout at 12v. Now i need the pulses from the 555 delay circuit to feed into the IC of any proposed digital display circuit operating at between 5v and 12. The above circuit operates at 12v and if any of your proposed digital displays works under a lower threshold, i would be pleased to feed the circuit through a calculated POTENTIAL DEVIDER to reduce voltage.

In essence, i am pleading for schematics and pin layout for a BCD,7 segment display circuit.

Cheers !
 
Last edited:

beenthere

Joined Apr 20, 2004
15,819
Apply the BCD to a 4511 7 segment driver - I am suggesting the CD4511 as yout Vcc is 12 volts. The 4511 has active high outputs, so use a common cathode display.

Get a data sheet for the CD4511 and another for the 7 segment display.
 

Thread Starter

Giggabyte

Joined Sep 19, 2008
15



Hie, by means of a simple diagram can someone assist by showing where to input the clock pulses( from my 555 timer) I suppose the circuit is now intact as it is above meaning i do not need another ic to drive the 4511 except the output pulses from the timer. I am currently not on my lab desk to build the circuit yet for testing.

Thank you
 
Last edited:

SgtWookie

Joined Jul 17, 2007
22,230
You also need a BCD (Binary Coded Decimal) counter like a 4518 that will supply inputs A0 through A3 to the 4511.
You supply the BCD counter with clock pulses from your timer's output.

You may find it easier to use a 4026 or 4033 IC; they take a clock inpulse, have an internal counter, and drive 7-segment displays directly.
 

Thread Starter

Giggabyte

Joined Sep 19, 2008
15


Which other pins go into the 4511 from the 4518 besides the A0 to A3 . The pulses from the 555 timer should be connected to which pin in the BCD (4518) !
 

SgtWookie

Joined Jul 17, 2007
22,230
Did you look at a datasheet for the 4518?

Here's a page with a pin-out diagram: http://www.kpsec.freeuk.com/components/cmos.htm#4518
You connect QA through QD of counter 1 to A0 through A3 of the 4511.
The ENABLE pin (2) for counter 1 must be connected to Vdd to allow counting.
Your clock goes to pin 1, the clock for counter 1.
The RESET pin (15) must be held low to allow counting. If it's high, the count is reset to all zeros.

Note that ALL UNUSED INPUTS for 4000-series CMOS devices must be connected to either Vdd or Ground. Leaving inputs disconnected ("floating") will cause big problems.
 
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