Olympic rapid fire training aid

Thread Starter

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
8,310
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
 

Thread Starter

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
8,310
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.
 
Last edited:

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
5,397
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.Range Timer 00000.jpg
 

Thread Starter

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 1 0.1 microfarad
Cap 2 0.1 microfarad
Cap 3 100 microfarad
Cap 4 10 microfarad
Cap 5 10 microfarad
Cap 6 0.1 microfarad
Cap 7 0.1 microfarad
Cap 8 1 microfarad ???
Cap 9 can’t find one ?
Cap 10 0.1 microfarad
Cap 11 10 microfarad
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 ?
 

Thread Starter

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 ?
 

Bernard

Joined Aug 7, 2008
5,397
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.
 
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