How do I create a Digital VU meter using 7408 IC ??? analogue VU meter no problem, seriously stuck is this possible using AND gates in a 7408 chipset?

 

hi SJ,
Welcome to AAC.
Is this a homework assignment.?
E

 

Yes it is and I am stuck giving the parts and been told it can be done, but checking forums and website all I see is analogue and not digital

 

hi SJ,
You say the 7408 and AND gates, are you only allowed to use these types.?
Do you have a draft specification of the DVU .?

As this is homework, post your best attempt and we can then guide you.
E

 

Hello E

I have upload a draft specification I have been working on, x3 switches, x7 LED and x1 7408 AND gate, power is 5.5 volts, so what I need to know am I on the right track, Digital is switches with 1's and 0's, the switches acting and flipping when an audio signal is play and the frequency changes the LEDS to light up, so I need to work on the audio input into the circuit and also requiring additional components. Thanks SJ

 

hi S,
Please confirm that you mean a Digital Volume Meter, I would also ask you to check with your tutor regarding the 7408 [AND gate] that must be used for this project.
You must also decide if you want a Volume Indicator or an Audio Frequency indicator.

A LM3915 is often used for Volume/Amplitude 'logarithmic' indication.

Frequency indication would require frequency selection amplifier/components to pick off the audio frequencies required.

E

 

The LM3915 is now obsolete, but you may be able to source one from old stock somewhere.

 

1) Why use an antique TTL IC?
2) A VU meter uses audio to indicate the loudness, but your circuit has no audio input.
3) What do your switches do? To set a binary input?
4) Why do the LEDs have no power connection to their anodes?
5) Are the seven LEDs in a 7-segment display to show a number? Then look at the datasheet of an old 7448 BCD to 7-segment driver that has many AND gates in it.

 

1) Why use an antique TTL IC?
2) A VU meter uses audio to indicate the loudness, but your circuit has no audio input.
3) What do your switches do? To set a binary input?
4) Why do the LEDs have no power connection to their anodes?
5) Are the seven LEDs in a 7-segment display to show a number? Then look at the datasheet of an old 7448 BCD to 7-segment driver that has many AND gates in it.

Because this is a homework assignment and he has been told to use an antique TTL IC

 

Teachers always use the same old stuff that they were taught about when they and the stuff were young.