Need Help on how to build 7 - Segment Display circuit with Series of LED's

[barbaro]

mister_rf

thanks a lot again for all your help.

 

[barbaro]

mister_rf

I now had the cghance to visit my electronics store to p/u my parts...

Unfortunately, couple of the IC's weent available. So, I had to p/u a different ones.

CD4093 - OK
CD4510 - not available so, I replaced it with 74LS193 instead.
74HC47 - not available either and I replace it with 74LS47

Are the replacement compatibble to each other or should we modify the schematic to accommodate the IC code changes?

Please advise ASAP.

Thanks a lot.

 

[vinodstanur]

74 Series Logic ICs

 

[mister_rf]

74LS193 is an UP/DOWN MODULO-16 Binary Counter, better to use 74LS192 UP/DOWN BCD Decade Counter.
Pinouts of the circuits has been changed, need to redraw the schematics.

 

[barbaro]

mister_rf

Sorry to always bother you...

- is it possible to just use the 74LS193? Coz I can't return the IC anymore. Also, will be so kind enouigh to redraw the schematic then because of the pinout changes?

Please advise.

Thanks so much.

 

[mister_rf]

I don’t have all details about the power supply, you have mention to use 9V, but that’s a battery 6LR61 type?
Initially ‘the project’ was based on CMOS chips and they work with a broader range of power supply voltages. While TTL ICs all require a power supply voltage of 5V, CMOS works with a wider range of power supply voltage – usually anywhere from 3 to 15V.
So we have planned 74HC47 = CMOS power supply 3 to 15V.
We have changed for 74LS47 and 74LS193 (Low-power Schottky TTL) so we need now also a 5V power supply. This mean to add an extra circuit (a Positive Voltage Regulator) to obtain 5V from 9V.

In order to use the 74LS193 (instead of a 74LS192), we need also additional gates, so it’s not so simple, better to buy directly the ‘192’ series. Preferable to buy CD40192 presettable BCD Up/Down Counter or TTL series 74LS192.

 

[barbaro]

Hi mister_rf

The power supply is not an issue. I can always change it into 5V. Also, I can change the 74LS193 into 192 series. I'm located in Canada and I don't know why there's not much of the CD*** IC's around. Please recreate the schematic based on the ff;

- CD4093
- 74LS47
- 74LS192 (or if possible I can cahnge it to CD40192)
- using 5V power supply.

Please and thank you.

 

[mister_rf]

Let's try this way. :grin:

 

[barbaro]

mister_rf

Thanks a lot. So, the CD4093 will stay the same? So, this is a 5V power supply now correct?

Please advise.

Regards...barbaro

 

[mister_rf]

LEDs still need to use a 9V power supply (LEDs in series), all other points marked +V to be connected at +5V.
No need to use the CD4093 this time.
All resistors (except R1 to R14) 100k.
Capacitors C1 and C2 between 22nF-100nF.
Don’t forget about 4 decoupling capacitors (4 ICs only this time).

 

[barbaro]

mister_rf

So, there will be two power supplies. 9V for the LED's and I have to connect another power supply which is the 5V.

Thanks for pointing out the CD 4093 not needed anymore.

---------- Post added at 15:49 ---------- Previous post was at 15:42 ----------

mister_rf

The C1 and C2 type of capacitor do I need?

 

[mister_rf]

C1 and C2 0.1µF any type, ex monolithic ceramic capacitors/multilayer/plate ceramic capacitors/Resin Dipped Ceramic Capacitors

---------- Post added at 20:57 ---------- Previous post was at 20:56 ----------

You need a single power supply and a LM7805 voltage regulator to obtain 5V from 9V.

 

[barbaro]

mister_rf

Thanks. I just went to look for the 74LS192 / CD40192 IC's and both are not available in stock don't know when it will arrive. It was too frustrating, I was really anxious about your nre revision. Is it possible to just use the 74LS193 and redo the schematic to allow the change. You mentioned to add gates. Is that supposed to be the function of the CD4093?

Please let me know if this is possible. Change the schematic for this changes below;

- use CD4093
- 74LS193
- 74LS47

Thanks a lot again.

 

[mister_rf]

Any chance for 74HC192, 74HCT192, 74HC4510, 74HCT4510? :-D

 

[barbaro]

mister_rf

YES, I checked and the 74HC192 is available. So, does teh schematic change using this IC? and by using this, I don't need the CD4093 anymore correct?

Pelase advise.

Thanks,
barbaro

 

[mister_rf]

The 74HC192 are CMOS devices and are pin compatible with low power Schottky TTL 74LS192. Problem solved, use the last schematics (post #48).

 

[barbaro]

The 74HC192 are CMOS devices and are pin compatible with low power Schottky TTL 74LS192. Problem solved, use the last schematics (post #48).

_________________________________________________________________________________

mister_rf

I had picked-up the IC already 74HC192. I will start putting the circuit together tonight.

Question:
You mentioned that to obaint the 5V from a 9V power supply, we need to add an extra circuit (a Positive Voltage Regulator). How does this apply> I'm just curious.

Please advise.

Thanks.

 

[mister_rf]

The LM7805 voltage regulator is a common solid state device that steps DC voltage down from voltages higher than 5V down to 5V DC. The 7805 is that it is very common and need only to insert a 0.1uF ceramic capacitor from the input to ground and also a second one from the output to ground. To keep the regulator cool, you should use a small heatsink to disperse the heat.

**broken link removed**
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http://www.sparkfun.com/datasheets/Components/LM7805.pdf
Linear regulator - Wikipedia, the free encyclopedia

 

[barbaro]

mister_rf

Thanks again...I will adapt into the 7805 parameter. The one that need only to insert a 0.1uF ceramic capacitor from the input to ground and also a second one from the output to ground.

Regards,
barbaro

 

[barbaro]

mister_rf

Finally started the project on a breadboard. I'm on the first digit circuit and I've connected all the segments with 150 ohms resistors following the pinout connection based on the data sheet for 74LS47. I've also connected lines to the 74HC192 and used 4 pin tact switches for B1,B2 and B3. I used 47uF capacitors. I've also added a cuircuit (the volt regulator) using 0.1 uF connecting the GND to all the rest of the GND connections and attached the + (no. 1 on diagram layout) to the input of teh regulator including the GND for the 9V connection from the 7 Seg display. The output of the volt regulator is connected to all the +V that should get the 5V power supply.

Question: If all the connections are good and on with their proper pinouts, should I be able to test with just the one digit or shoul I also finish the other digit "tens" with their IC's connected to the "ones" digit IC's?

Please let me know. As I'm really anxious of having to his workout ok. Also, I've purchased a multimeter but, how should I test the probes just to make sure my connections are OK. or is this even opssible without connecting the main power suplpy?

Please and thank you.