IC Trainer Kit?

[Electroenthusiast]

How exactly is the Circuitry inside a IC Trainer Kit?
I'm asking ' Are all connections grounded?'; Will they use Pull-Down resistors for all Pins?
I got this question because https://www.electro-tech-online.com/threads/ic-7404-not-gate-doubt.103937/ ...>>> High Impedance State.
A Typical Kit that i use is Here...
**broken link removed**

 

[Hero999]

This link is broken, I fixed it.
https://www.electro-tech-online.com/custompdfs/2010/03/Digital20IC20Trainer20Kit.pdf

How are we supposed to know?

There's no schematic.

I doubt it uses crappt TTL gates, it's more likely CMOS, in which case it's likely to have pull down resistors built-in.

 

[Electroenthusiast]

These type of Trainer Kit show two possible states at the output(HIGH/LOW).

Suppose i want to do a Digital Design using a PCB/Breadboard,
am i required to use Pull-Down resistor at every input of each and every IC?
so that there will be no High impedance state.

A circuit something like this...


What will be the state when Switch is OPEN?
What will be the case when i use a component that gives output +Vcc/ 0 alternatively?

 

[Hero999]

I've just told you, I don't know because there's no schematic.

I suggest you ask the manufacturer.

 

[mneary]

The chip in your example cannot be a 7404 because it has 16 pins instead of 14.
Therefore we can only guess the function of the pins you are using.

 

[Electroenthusiast]

The chip in your example cannot be a 7404 because it has 16 pins instead of 14.
Therefore we can only guess the function of the pins you are using.

I just told to consider it as an some Inverter IC...
I want to know the concept thats all(My previous post has my ques).
Trainer kit not required

 

[Hero999]

Different logic families have different internal structures.

TLL gates are designed so the inputs default to high and need pulling low so the risk that the input will pick-up noise is very low unless the leads are very long.

CMOS gates are designed to have a very high input impedance and there is no default setting for the inputs, so if they're left unconnected, the input can pick up noise and be unpredictable.

You need to know what logic family the IC uses, there is no hard and fast rule.

Modern ICs tend to be CMOS, TTL is obsolete.

 

[Electroenthusiast]

Different logic families have different internal structures.

TLL gates are designed so the inputs default to high and need pulling low so the risk that the input will pick-up noise is very low unless the leads are very long.

CMOS gates are designed to have a very high input impedance and there is no default setting for the inputs, so if they're left unconnected, the input can pick up noise and be unpredictable.

You need to know what logic family the IC uses, there is no hard and fast rule.

Modern ICs tend to be CMOS, TTL is obsolete.

Thank you, it answered me...