I'm from South Africa and we are experiencing Load Shedding for the next 3 years or so. This means that our local Electricity company turns the power off for up to 3 hours about 5 times a week. I would like to play music during the down time (typically 2 hours), so I thought this is the perfect excuse for a project.
I'm thinking Li-ion Battery with charger permanently connected, through a small Class D Amp circuit, into small drivers (2 - 4 inch) typically 5W - 20W per channel. I would like to make up for lost bass with a good cab design and it all needs to be on a reasonable budget (Else I can just buy off the shelf).
My local electronics store only has one amp as a potential candidate TDA8925, datasheet below) and I wanted to get some feedback regarding the amp, and suggestions for the power source and drivers.
http://media.digikey.com/pdf/Data Sheets/NXP PDFs/TDA8925.pdf
Looking forward to your response!
I'm thinking Li-ion Battery with charger permanently connected, through a small Class D Amp circuit, into small drivers (2 - 4 inch) typically 5W - 20W per channel. I would like to make up for lost bass with a good cab design and it all needs to be on a reasonable budget (Else I can just buy off the shelf).
My local electronics store only has one amp as a potential candidate TDA8925, datasheet below) and I wanted to get some feedback regarding the amp, and suggestions for the power source and drivers.
http://media.digikey.com/pdf/Data Sheets/NXP PDFs/TDA8925.pdf
Looking forward to your response!
not easy to DIY Li battery chargers , cell balancing is key, bsides the usual safety issues.
sorry for you have these troubles,
maybe plan your project a little wider in scope.
I would use a large lead acid battery and an inverter, DIY UPS thing, then you can listen to music, watch TV , and have internet and / or PC use. when I have a extended blackout I run and connect an inverter up to my truck and run an extension cord. since you know it's coming you can set up a better system.
BTW most commercial Li battery chargers are available to run off 12V , they are cheap and flexible. the always connected batt. charger to your gear is the trouble.
It doesn't have to be Li-ion, but I'm not going for a wheelbarrow full of battery and inverter setup... I typically want to put a 10" x 10" x 10" size restriction on the project (everything included).
I have the lights sorted with LED Strips hooked up to my Burgler Alarm battery that has it's own charging system.
The only other thing I would like is a bit of background music that's slightly more powerful and with better range than my cellphone or laptop to help drown out the sound of my idiot neighbour's generator while I chat with the missus about our useless energy company among other things... I'm not going for audiophile quality, simply acceptable entry level background music.
It's would be nice if the system is portable so I can take it camping / fishing every so often...
I have the lights sorted with LED Strips hooked up to my Burgler Alarm battery that has it's own charging system.
The only other thing I would like is a bit of background music that's slightly more powerful and with better range than my cellphone or laptop to help drown out the sound of my idiot neighbour's generator while I chat with the missus about our useless energy company among other things... I'm not going for audiophile quality, simply acceptable entry level background music.
It's would be nice if the system is portable so I can take it camping / fishing every so often...
Kistradio en Kratradio Specialist - Modules - Versterkers - MaxAmp 12V Class-D versterker met JST-PH connector
I use one of these on my sailboat. Since my battery capacity is small, I chose these for their efficiency. I power 2 small 2-way 90 dB "outdoor" speakers. The quality of sound is very respectable...
I use one of these on my sailboat. Since my battery capacity is small, I chose these for their efficiency. I power 2 small 2-way 90 dB "outdoor" speakers. The quality of sound is very respectable...
What size battery will I need to power the following combination:
Amp: TDA8925 class-D, 2 x 15W @ 8 Ohm, 2 x 20W @ 6 Ohm.
http://media.digikey.com/pdf/Data Sheets/NXP PDFs/TDA8925.pdf
2 x Speakers: Pioneer 4" 30W (RMS), 4 Ohm, 88db, 45 Hz to 26 kHz.
PIONEER TS-G1014 SPEAKER - PIONEER - www.hificorp.co.za
B.T.W. will I run the Amp too hot at 4 Ohm...?
Amp: TDA8925 class-D, 2 x 15W @ 8 Ohm, 2 x 20W @ 6 Ohm.
http://media.digikey.com/pdf/Data Sheets/NXP PDFs/TDA8925.pdf
2 x Speakers: Pioneer 4" 30W (RMS), 4 Ohm, 88db, 45 Hz to 26 kHz.
PIONEER TS-G1014 SPEAKER - PIONEER - www.hificorp.co.za
B.T.W. will I run the Amp too hot at 4 Ohm...?
I have not seen the TDA8425 that you cite used or offered prolifically like the TPA3116D2. The 3116 is 90% efficient and has very low idle current. It can give a clean 40watts per channel but with 12v can easily handle the 15w range. They sound very nice too. Look on class D forum for tips. Another option is TDA7492 that has similar power as 3116. Both of these amps can be bought between $6 and $25 fully build boards that just need a power supply.
I really want to use common chips, but the TDA8425 is what's readily available to me (Else I have to import).
Apart from car audio speakers (Starting from 4" drivers around 10W) I found 3 smaller speakers available to me:
100mm 10W Bass Round Speaker, 8Ohm (AMT30G) [AMT30G] - R252.29 : Yebo Electronics
100mm 15W Full Range Round Mylar Speaker (AMT31G) [AMT31G] - R178.90 : Yebo Electronics
100mm 30W Mid Range Shielded Chassis Speaker (AMT32G) [AMT32G] - R287.28 : Yebo Electronics
Will these speakers work with the TDA8425 Amp? What size power supply will power it for 3 hours or more?
Another smaller driver option:
75mm 10W Full Range Round Speaker, 8Ohm (AMT29G) [AMT29G] - R172.37 : Yebo Electronics
75mm 10W Full Range Round Speaker, 8Ohm (AMT29G) [AMT29G] - R172.37 : Yebo Electronics
Hi,
IMHO you should just buy something like a USB powered
pair of laptop speakers or a portable rechargeable speaker.
What you are trying to do is not remotely simple and you
seem to have no idea of the complexity that is involved.
rgds, sreten.
These massively improve a laptop and can run off its battery :
http://www.amazon.com/Logitech-S150...pebp=1436312474710&perid=0YRKBN79F6F70YXT05EV
IMHO you should just buy something like a USB powered
pair of laptop speakers or a portable rechargeable speaker.
What you are trying to do is not remotely simple and you
seem to have no idea of the complexity that is involved.
rgds, sreten.
These massively improve a laptop and can run off its battery :
http://www.amazon.com/Logitech-S150...pebp=1436312474710&perid=0YRKBN79F6F70YXT05EV
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I assume this is one of the most popular boards available, right?
High Quality New Arrival 50Wx2 Official version Finished TPA3116D2 Class T Digital Power Amplifier Board-in Integrated Circuits from Electronic Components & Supplies on Aliexpress.com | Alibaba Group
Only funny thing I noticed is that the Operating frequency is stated as 20Hz to 6kHZ, instead of 20Hz to 20kHz... Is this a typo or am I looking at the wrong board for my application?
Is this board reasonable in terms of power consumption? I want to run from batteries and according to the TPA3116D2_Boards thread on here I'm expecting to draw around 4.5A @ 12V to run 2 x 4 Ohm speakers at 25W each... is this about right?
High Quality New Arrival 50Wx2 Official version Finished TPA3116D2 Class T Digital Power Amplifier Board-in Integrated Circuits from Electronic Components & Supplies on Aliexpress.com | Alibaba Group
Only funny thing I noticed is that the Operating frequency is stated as 20Hz to 6kHZ, instead of 20Hz to 20kHz... Is this a typo or am I looking at the wrong board for my application?
Is this board reasonable in terms of power consumption? I want to run from batteries and according to the TPA3116D2_Boards thread on here I'm expecting to draw around 4.5A @ 12V to run 2 x 4 Ohm speakers at 25W each... is this about right?
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I'm thinking of driving these little speakers with the board above...
db351 - Polk Audio
Now I just need to worry about the re-chargable power supply and the enclosure.
db351 - Polk Audio
Now I just need to worry about the re-chargable power supply and the enclosure.
The always connected alarm charger means they use a tiny trickle charger. depending the 'state of charge' it may take a few days to come back up to full charge level. With an added load along with an almost daily depletion, expect to run down the battery to zero a few times and you'll be needing a new SLA very soon. I'm sure the alarm engineers built the backup system very lean an mean, its not bulging with overcapacity like some might assume.
on another note, perhaps copy same type of system they use and beef up the trickle current to an extra amp or so for your always connected audio amp load. You'll still need to hook-up a 'fast charger' manually to top off both systems and equalize the cells on a regular schedule if you care about battery longevity. BTW on 3-14 Ah SLA battery don't ever expect full 100% available draw down on regular basis. these type of backup batteries expect not to be used at all, but maybe 3 or 4 times in their whole lifetime.
The techies that installed my alarm said my small system probably won't draw more than 1 amp. The entire 5m LED strip measured around 1.6A and I only installed about 3m, and most of the time I don't even switch everything on.
The alarm battery is 7Ah and if I use less than 2A in total for two hours I should never run the Gel Battery down more than 50%. According to the battery supplier this will not hurt the battery...
yes 50% of the new battery Ah is a good target, but Ah capacity decreases with age and any abuse. check the trickle charging system, it may not bring up the SOC to 100% but only after a few days plugged in. you can estimate the alarm load by reading the manual, AFAIK they design for ~8hrs brand new, so little less than 1 Amp sounds right.
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Being in South Africa,
How about a solar panel and a 12V car battery?
I have seen solutions (which I might use when trying to set up a camper style vehicle here) where a solar panel is attached to a battery tender and a 12V car battery. That should provide more than enough power to play music over your 2-3 hours of downtime.
How about a solar panel and a 12V car battery?
I have seen solutions (which I might use when trying to set up a camper style vehicle here) where a solar panel is attached to a battery tender and a 12V car battery. That should provide more than enough power to play music over your 2-3 hours of downtime.
That appears to be the clone of the YJ blue/black but with some mods like an LED and pads for protection diodes underneath. Mine sounds fine. $12 is a good price and if you need to swap out the main caps with know n high quality ones. 6kHz is a typo. This is one of the best amps for power consumption. If you put it into stamdby or shutdown mode via SDZ pin, it hardly consumes any power. When on it is 90% efficient.
25 watts rms continuous is a lot of power, pretty loud - full blast. Are you really playing full blast?
For 12v supply, max rail voltage is probably 10v.
P=V^2/R=10^2/4=25watts. I=V/R=10/4=2.5A per channel or 5A total for 25w/ch/
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