LED , transistors Quiz buzzer circuits have been available numerous in number yet we face many problems in most of the circuits and some cost much. Here is a perfect and cost effective electronic circuit which can be used for quiz in schools and colleges. The switches are given to each participating competitors and the respective bulbs can be placed before them to determine which team pressed the switch first. Lets look into the working of this quiz buzzer circuit. This IC takes eight inputs enabling eight teams to play with it.
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What problem you are facing? Thanks also for reminder on LED driver, I had dropped down to logic states! You people are very helpful, Thanks. The current I1, R7 and Q2 replace the push-button 7l4s in order to simulate the circuit. SCR Silicon Controlled rectifier was connected to the output pins of the IC and along with it diodes are also connected.
Notify of all new follow-up comments Notify of new replies to all my comments. Last edited by sharikbaig; 27th August at Notify of all new follow-up comments Notify of new replies to all my comments. PV charger battery circuit 4. Synthesized tuning, Part 2: The beauty of this simple circuit is it actually debounces your switch, i.
This single chip solution plus solenoid drivers worked very well ModelSim — How to force a struct type written in SystemVerilog? Distorted Sine output from Transformer 8.
The only potential issue is both switches operating together as the output becomes indeterminate. Do I need pull up resistors or does this sound like bad chips. Relay latching in AT89C51 based circuit But when the Latch Enable Pin was pulled low, the data will be latched so that the data appears instantaneously providing a Latching action. PNP transistor not working 2. The switches are given to each participating competitors and the respective bulbs can be placed before them to determine which team pressed the switch first.
The following two tabs change content below. Enable gates pin 11 high 2. Compare latch based and register based design 5. I mean which part of circuit is troubling you? OE is held tied to ground. Datasheet of 74LS is also attached.
How reliable is it? Frank Donald October 27, 2 Comments. Measuring air gap of a magnetic core for home-wound inductors and flyback transformer 7. The initial state of the LED is off U3 output is low. 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.
Therefore almost every post I write would usually be updated several times till it reaches its saturation: As long as output is enabled which it is — pin 1 is Low For this latch to hold data, you must do the following: It doesnt latch in HIGH state. When the OE pin is low input data will appear in the output. These small chips were 18 or 24 pins?
IC Datasheet: 74LS373 Data Sheet
IC 74LS forms the 74sl heart of this circuit and it was a transparent latch which consists of a eight latches with three state outputs. Thanks also for reminder on LED driver, I had dropped down to logic states! Projects LEDtransistors. Lets look into the working of this quiz buzzer circuit. AF modulator in Transmitter what is the A? Originally Posted by kripacharya.
IC Datasheet: 74LS373