74LS, 74LS Datasheet, 74LS Octal D Flip-Flop, buy 74LS, 74LS pdf, ic 74LS These 8-bit registers feature totem-pole 3-STATE outputs designed specifically for driving highly-capacitive or rela- tively low-impedance loads. Operation and working of Latch IC (74LS) Working of Latch IC and operation of Flip flop to perform as buzzer latch IC its.

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Quiz buzzer circuits have been available numerous in number yet we face many problems in most of the circuits and some cost much. You have LE fixed High, hence output equals input Here is the Link for the datasheet kindly take a look at the electrical characterstics, hope this helps. Turn on power triac – proposed circuit analysis 0. Results 1 to 20 of Problem with 74LS latching!

Can anyone please help me sort out the problem?. This IC operates with maximum of 5 V and widely used in many kinds of electronic appliances.

Compare latch based and register based design 5. Lets look into the working of this quiz buzzer circuit. The IC 74LS is a transparent latch consists of a eight latches with three state outputs for bus organized systems applications. Frank Donald October 27, 2 Comments.

Any other idea is also welcomed. The circuit was powered with 5V power supply and as you can see that the switches were connected directly to the power supply so when the switch is not pressed it gives low signal to the input pins D0-D7.


Heat sinks, Part 2: As long as output is enabled which it is – pin 1 is Low For this latch to hold data, you must do the following: What is the function of TR1 in this circuit 3. The following two tabs change content below. I have 5V on D, but only get 3. CMOS Technology file 1. And the high output signal further switches the SCR on and thereby the respective bulb of the team will glow and also the transistor T1 connected to the Buzzer will switch the buzzer ON.

This single chip solution plus solenoid drivers worked very well And diodes was used to allow the forward flow of current from the output pins of the IC and thereby switching the transistor ON and thus perform the Latching operation.

Each momentary switch would latch a solenoid valve and when activated switch off the others valvesa bit like a manual washing machine.

Frank Donald is an Electronics and Communication Engineer who loves building stuff in his free time. The time now is They were a great introduction to simple logic and 74lls373 which is a bit lost in todays massive chips. In this point of time the IC will not respond to any of the input signal given by any other switches to 74la373. Do I need pull up resistors or does this sound like bad chips.



Being not a machine, I always do silly mistakes or miss important things. I tried this circuit in multisim. Originally Posted by KerimF.

What problem you are facing? SCR Silicon Controlled rectifier was connected to the output pins of the IC and along with it diodes are also connected.

OE is held tied to ground. Quiz buzzer circuit can be initialized by switching ON the power supply and once it was ON the quiz buzzer will be ready to use.

This low state in the LE pin enables the latch of the IC thereby providing continuous high signal in the output pin.

Datasheet of 74LS is also attached. PV charger battery circuit 4. Also I may not reply at time.

Frank Donald is an Electronics and Communication Engineer who loves building stuff in his free time. Dec 248: Part and Inventory Search.

Quiz Buzzer Circuit using IC 74LS – Gadgetronicx

Last edited by sharikbaig; 27th August at Our main server could be out of service anytime. Here is a perfect and cost effective electronic circuit which can be used for quiz in schools and colleges. Latest posts by Frank Donald see all. Distorted Sine output from Transformer 8. Here is an i http:

Last modified: April 29, 2020