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7 segment display

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pfofit

Active Member
The "complete" helps a bit.

You are way overkill on all those gates.

Just place a 12 volt relay across each solenoid and use a contact from each relay to be SW1 and SW2 for the 4511 schema I edited earlier. The two contacts and a couple diodes and a transistor with decode the solenoid selections to BCD, whether it is done manually or automaticly.

Since you have 12 volts, use that for the 4511 circuit instead of five volts. If you do use 5V then swap the segment resistors to 180 ohms or they will be mighty dim.

A tip41 can handle 6 amps so a little extra from a dinky 12volt relay is nothing against the solenoids.

cheers
 
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strokedmaro

New Member
I can see what you mean...I knew thats was not the best way to do it, but would it work. I want to see if i understand how to use gates.
 

Ambient

New Member
tying the outputs of two gates will not work properly, us another logic gate if they need to be OR'd
 

strokedmaro

New Member
Ambient said:
tying the outputs of two gates will not work properly, us another logic gate if they need to be OR'd
Yeah, I figured that one out when I put tried to get it to work in a logic simulator...used an OR gate as you suggested and it works fine. THANKS!!
 

jbeng

Member
You could also program an EPROM to do this. A huge waste of memory space in such a device (using only 4 locations), but you can get them real cheap, often salvage them for free. Program it with 4Fh in address 00, 5Bh in addr 01, 66h in addr 02, 06h in addr 04. The segment data is as follows: Seg A = D0, Seg B = D1, Seg C = D2, etc. All you need after that is a driver to provide enough current to drive the display segments. You could even do display dimming by PWM'ing the -CE or -OE pin on the EPROM.
Jeff
 
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