Skip to main content

Going for Gold


The title refers to a popular TV game show where the contestants each have a big button.  The  game show  host  asks  a  question and the first contestant to press their but-ton makes an illuminated indicator light up on their desk. The other contestants’ buttons  are automatically inhibited, so that everyone can see who was the first contestant to press their button, and so is allowed to answer the question. The project described here shows how to build a similar sortof  refereeing device yourself, using simple resources and without needing a microcontroller, which is  pretty rare these days! The basic circuit is for  just two contestants, but the modular design  means it can easily be expanded.

 

Circuit diagram :

 Going for Gold-Circuit-Diagram

Going for Gold Circuit Diagram

 

The diagram shows three buttons: S2 and S3  are the buttons for the two contestants, S1 is  the button for the host, which allows them to  reset the circuit before each fresh question.  The ‘brains’ of the circuit is IC1, a 4013 dual D-type flip-flop, of which only the Set and Reset  inputs are used here. This circuit can handle  quite a wide supply voltage range, from 3 to  15 V, and so the project can easily be run off a 4.5 V battery pack (the power consumption is minimal).

 

IC1 is armed by pressing S1 (reset). In this  state, the non-inverting outputs (pins 1 and  13) are at 0 and the inverting outputs (pins 12  and 12) are at 1. Hence line A is pulled high  by R1, since diodes D2 and D4 are not biased  on. If contestant 1 presses button S2, the  non-inverting output of flip-flop IC1a goes  to logic 1, and LED D1 lights via T1 to indicate that contestant 1 has pressed the but-ton. At the same time, the flip-flop’s invert-ing output goes to logic 0, making diode  D2 conduct. Line A is now pulled down to 0,  and consequently contestant 2’s button S3  can no longer trigger the second flip-flop.  The reverse happens if it is contestant 2 who  presses their button S3 first.

 

The circuit can be extended to 4 or 6 contest-ants (or even more) by adding a second or  third (or more) 4013 IC. All you have to do is  repeat the circuit (minus R1, R2, and S1) and connect to the A, B, Vdd, and 0 V lines on the right-hand side.

 

Author : Joseph Kopff - Copyright : Elektor


Labels:

Comments

Post a Comment

Popular posts from this blog

A basic Arduino Solar PV Monitor

I have just recently had solar pv installed, mainly to future proof my energy costs, I do not expect it to be like drilling for oil in my back garden, however the return looks to be encouraging. The install gives you another single unit meter, from this you will see the total amount the panels produce, but that is about it. I wanted to know how much the production was as it was happening, I discovered the light blinks on the front of the meter will flash 1000 times for each kWh of electricity which passes through. The rate of the flashing of the LED tells you how much power is currently passing through the meter. [ ]
Post a Comment
Read more

Apple releases TV spot for new iPods

Apple has just released a fun commercial to showcase its new line of iPod players and the various colours they come in. The TV spot titled ‘Bounce’, has a bunch of colourful iPod touch, iPod nano and iPod shuffles er…bouncing to music. With all that colour and dancing and bouncing, you may forget that Apple’s latest gen line of iPods has some other awesome features. For instance, the fifth gen iPod touch comes with Siri, 4-inch retina display and an A5 chipset. Maybe the next ad will showcase some of these features with less bouncing.link
Post a Comment
Read more

3 Channels Audio Splitter Amplifier Circuit Diagram using TL084

This is the schematic diagram of 3 channels audio splitter amplifier circuit which built using op-amp IC TL084. The 3 channels amplifier output distribution applies a single TL084.   3 Channels Audio Splitter Amplifier Circuit Diagram The very first step is to capacitive coupling having a p. 1.0 ~ electrolytic capacitor. The entries are railways Vee Y2 or 4.5 V. This enables working with an individual 9V power source. A voltage gain of 10 (1 M?/100 Kohm) is obtained in the first stage, as well as the other three floors are connected as a unity gain voltage followers. Every single output stage drives independently through an amplifier output 50 pF capacitor towards the resistance of 5.1 k ohm load. The response range is flat from 10 Hz to 30 kHz.
2 comments
Read more