# Olympic rapid fire training aid

#### MarkAB

Joined Feb 27, 2016
80
Hi can anyone help me in building a circuit for a training aid.

It must have a start switch that after pressed gives an audible beep and shows a red led, after a 1 minute delay an audible beep signalling the start of a 7sec delay to end with start of a 4 sec green led(red off) followed back to the red led and restarts the initial beep and 1 min count.

switch -beep- 1min red led - audible beep - 7sec - 4 sec green led (red off) - back to start beep and 1min red led on

It would be a huge advantage if the timings could be programmable.

This product is the closest available to purchase but not quite what I need.
http://www.edinkillie.co.uk/ecatalog/techro-box-p-585.html?cPath=23_25

#### AnalogKid

Joined Aug 1, 2013
8,298
This can be done with a few CMOS chips, but it is an excellent candidate for a PIC, Rpi, small Arduino, etc.

ak

#### AnalogKid

Joined Aug 1, 2013
8,298
Your description amounts to a 71 second pattern with three decoded states at 60, 67, and 71 seconds. A CD4521 can provide the binary count with crystal accuracy without calibration. Decoding the three states takes a bunch of gates, or 10 small signal diodes and three resistors. So the first pass BOM is:
1 - CD4521
1 - 32.768 kHz watch "crystal"
1 - CD4093 or CD40106 (don't know which one yet)
10-12 - 1N914 / 1N4148 signal diode
3 - 2N7000 small MOSFET transistor (LED and beeper drivers)
5 - resistors
5 - capacitors

ak

#### MarkAB

Joined Feb 27, 2016
80
I am about to receive some 555 timers and will be playing with them on the bread board. Any ideas?

#### AnalogKid

Joined Aug 1, 2013
8,298
I'm not a big fan of long-delay 555 circuits. This can be done with three 555's in a ring, but it will take some messing around and extra parts to bet the trigger polarities and output functions correct.

ak

#### blocco a spirale

Joined Jun 18, 2008
1,546
Since this is just a "do something-wait-do something else.... etc." cycle, a cheap Arduino Nano clone running a modified version of the simple "blink" sketch is all you need. Don't worry if you've never programmed anything before, this is as easy and inexpensive as it gets.

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#### takao21203

Joined Apr 28, 2012
3,696
With old-school technology it will be hardwired and take two weeks.

With mcu it will take one or two days and the software can be changed by refreshing.

#### Bernard

Joined Aug 7, 2008
5,395
Here is one version: Missing is 1/2 sec. beep circuit, will add later. All Rs 10k except as noted, pots all 1 meg.
Q5 is power-up reset. Also missing line from top + to bottom +, Q4-8.

#### Bernard

Joined Aug 7, 2008
5,395
Beeper. Sounder,S , similar to Radio shack 273-060, 4-28V DC.

#### takao21203

Joined Apr 28, 2012
3,696
my reaction to people making such circuits at some stage was, sell them NE555 chips.

#### MarkAB

Joined Feb 27, 2016
80
Beeper. Sounder,S , similar to Radio shack 273-060, 4-28V DC.View attachment 105460
Wow thank you so much, this is great, will have to study this close as I am a newbie to electronics but I so much want to build this thanks.
Does this circuit connect to the other or are they separate ? please forgive me.

#### Bernard

Joined Aug 7, 2008
5,395
Beeper connects to other circuit.

#### MarkAB

Joined Feb 27, 2016
80
Here is one version: Missing is 1/2 sec. beep circuit, will add later. All Rs 10k except as noted, pots all 1 meg.
Q5 is power-up reset. Also missing line from top + to bottom +, Q4-8.View attachment 105459
Could you please check my shopping list

Cap 9 can’t find one ?
D1,D2 & D3 are all 1N4148 ?
3 x 1M POT
4 x 555 timers ( I have NE555p timers would these be ok?)
1 red & green led
12 x 10K resistors
200 & 300 Ohm resistor
47K resistor
is Q5 a NPN BJT ?

#### MarkAB

Joined Feb 27, 2016
80
Does anyone know of a good simulator I could try this circuit in so I don't blow anything up lol ?

#### Brownout

Joined Jan 10, 2012
2,390

#### Bernard

Joined Aug 7, 2008
5,395
Your shopping list looks good. C8 is 1 uF, diodes all 1N4148 or 1N914 or = .
NE555P, NE555N, Mc1455P are all the same, also comes in a TO5 can @ about 5 X more $. Q5, NPN like 2N3904. Are you making beeper later ? Do you have a solderless breadboard ? That is what I use, usually with some mistakes, the holes just seem to be getting closer together as the years pass. I would set it up one stage at a time & test. Temp. connect 555 pin 4's to + V, add power- up later. Temp. add resistor & LED to 555's output-P3 to watch progress. Watch for cap's polarity, re check every thing before applying power. Good luck. Note- Q2-8 missing connection to +V, Q3-8 not labled Thread Starter #### MarkAB Joined Feb 27, 2016 80 Your shopping list looks good. C8 is 1 uF, diodes all 1N4148 or 1N914 or = . NE555P, NE555N, Mc1455P are all the same, also comes in a TO5 can @ about 5 X more$.
Q5, NPN like 2N3904. Are you making beeper later ?
Do you have a solderless breadboard ? That is what I use, usually with some mistakes, the holes just seem to
be getting closer together as the years pass. I would set it up one stage at a time & test. Temp. connect 555 pin 4's to + V, add power- up later. Temp. add resistor & LED to 555's output-P3 to watch progress.
Watch for cap's polarity, re check every thing before applying power. Good luck.
Note- Q2-8 missing connection to +V, Q3-8 not labled
Yes I will be needing the beeper later.
Yes I do have a solderless breadboard but I have no idea how to brake this circuit down to stages?
Sorry to be such a bother but I am quite new to all this but I am very passionate about it thou.

#### Bernard

Joined Aug 7, 2008
5,395
Try hooking up Q1 & then Q2. Might use a different color LED so as not to confuse with R or G

#### takao21203

Joined Apr 28, 2012
3,696
I have small 1M pots. Saw them in a 1980s Mitsubishi VCR, searched for them quite a long time.