# 12v Sports Hooter And Amperage Advice

Discussion in 'General Electronics Chat' started by Ugraa, Mar 26, 2015.

1. ### Ugraa Thread Starter New Member

Mar 26, 2015
2
0
Hi first time poster here,

I have a few questions, I have planned to put together a small and cheap electronic relay circuit to power a hooter for my local touch football club using 2 small relay boards (see below link). Everything in the relay circuit works correctly and i have tested it with a 12v pc fan. I picked up a twin 12v air horn set that would usually be installed into a car to use as the hooter, however I neglected to take into account how much current the hooter compressor would draw (around 8amps). My 240v AC - 12v DC power supply only provides 1amp. As i have limited electronics knowledge and this was more of a project for myself, I now need to find out how/if I can provide about 8amps to power the compressor.

I started doing a little research and found a DC-DC booster which can apparently increase the voltage as well as amps(see below link). I would only need to maintain the original 12v DC voltage and increase the amps with the on board dial. This sounds too easy... maybe I am over thinking it.

If I were to replace the hooter with something that has a lower amperage draw, It would need it to still be loud enough to hear possibly a few 100 meters away at distant fields.

Final points
• Is a DC-DC booster a viable option
• Will finding a power supply with a higher amp output cause damage to my circuit
• Can a capacitor be implemented into the circuit which the compressor can draw from to run
I am open to all ideas and suggestions. Sorry if I come across a bit silly, but I am still only very new to the electronics world. Any help will be much appreciated.

References:
Cheers

Pat

2. ### MikeML AAC Fanatic!

Oct 2, 2009
5,451
1,066
Power in = Power out minus losses. If you boost voltage, you unboost current. If you boost current, you unboost voltage such that the product of Vin*Iin > Vout*Iout. (Laws of thermodynamics cannot be violated)

Me thinks you need a bigger power supply, or a big lead-acid battery. You can charge a big battery with your 1A supply as a charger; it just takes longer...

3. ### Ugraa Thread Starter New Member

Mar 26, 2015
2
0
Ok no worries, thanks for the reply. So if i was to get a 12v power supply that was say 6-8 amps that should do the trick.

4. ### djsfantasi AAC Fanatic!

Apr 11, 2010
2,911
881
If the hooter compressor draws around 8A, you need a supply that can supply 8A or more. 6A won't be enough.

5. ### MikeML AAC Fanatic!

Oct 2, 2009
5,451
1,066
How often, and for how long are you using the horn.?

If you are using a 12V Sealed Lead Acid battery of about 5Ah capacity, allowing for losses, you could operate the horn for a total of about 20min before the battery needs recharging. I am assuming that the battery is not being recharged during the game (no ac available), and would be recharged at home in between games...

I would need to know more about your 1A supply to determine if it is suitable as a battery charger or not...

6. ### bwilliams60 Active Member

Nov 18, 2012
734
94
Why don't you get yourself an air pig and just carry it around in a duffle bag? No compressor or electrical stuff to worry about. (Former hockey and soccer coach )