testing a cheap chip amp |
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Grinner
Registered User Joined: 02 December 2005 Location: essex Status: Offline Points: 407 |
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Posted: 02 January 2015 at 6:17pm |
so i had a few bits sitting around for a while, and i was bored.
thought i would test a few components. this is the amp. http://www.ebay.co.uk/itm/Board-2x50W-AMP-Board-with-Radiator-TDA7492-D-Class-High-Power-Digital-Amplifier-/141267392894?pt=UK_AudioTVElectronics_HomeAudioHiFi_Amplifiers&hash=item20e431597e this the step up converter http://www.ebay.co.uk/itm/New-DC-3-35V-To-3-5-35V-100W-LED-Voltmeter-Step-up-Adjustable-Power-Boost-Module-/141149814807?pt=UK_BOI_Electrical_Test_Measurement_Equipment_ET&hash=item20dd2f4017 ceiling speaker was given to me. dual voice coil jobby that has on board crossover a couple of videos showing it working. the speaker is sitting in a plastic plant pot at mo http://www.facebook.com/video.php?v=10152744757273145&set=vb.630683144&type=2&theater http://www.facebook.com/video.php?v=10152744152603145&set=vb.630683144&type=2&theater just need to either make a suitable box or find a little travel bag/case for it to fit in. so if you know where i might find 1 let me know. as i would like it to look neat for my daughter. for the 6quid investment, it makes a fair old noise, an sounds good too. also going to test it with some small 3" Cambridge pc speakers i have 4 of. an might try making a mini boominator |
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Edd Jordan
Young Croc Joined: 10 January 2008 Location: United Kingdom Status: Offline Points: 1364 |
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Very nice, like the power booster with voltage display. whats the battery pack you have there?
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I do a sideline in ply wood wheels.
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Grinner
Registered User Joined: 02 December 2005 Location: essex Status: Offline Points: 407 |
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the battery is from a bosch 10.8 drill.. it basicly has 3 18650 li po. and is only 1.3amp hour.
interestingly 1t shows 12.5 when fully charged. but done a test to see how long it would last connected up to 2 * 6ohm bookshelf speakers on friends boat on sunday. after 5 hours it was still giving out the same output even when the battery voltage dropped to 8.8v . an was very impressed. next test is to bridge it. an fit inside some 8&1" pa cabs i have. on paper it says 100w when bridged. i fully aware of what the specs say on amp and step up module. but so far goes beyound the stats given. no heat issues either on both. the voltage readout an voltage converter is cheaper than most volt meters available too. but is limited to 100 watts when input voltage is above 20v the combo of using both these modules seem perfect to me. all in all i had more fun playing with this £6 investment than a pint an 3/4 it would buy me in a pub. Edited by Grinner - 15 January 2015 at 4:44am |
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studio45
Old Croc Joined: 16 October 2007 Location: United Kingdom Status: Offline Points: 3863 |
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Cripes, don't run a 3s lipo battery down to 8.8v, that's only 2.9v per cell, well below the safe minimum voltage of 3.2v. According to all sources, it soon won't charge if you keep flattening it that much!
(LiPo voltages per cell: 3.2v= flat as pancake, 3.7v = average over discharge cycle, 4.2v = full charge)
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Studio45 - Repairs & Building Commotion Soundsystem -Mobile PA
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Grinner
Registered User Joined: 02 December 2005 Location: essex Status: Offline Points: 407 |
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i only realised it went down that low when i flicked the meter back an turned it of immediately.
as had it on the output. an was gobsmacked it stay level an steady with the bass it was pumping. only flickering 0.1 of a volt. i might also add the batt pack came from a knackered drill that has been abused for a year an then broke. but testing is as testing does. an was well sloshed by that point in the belief that the battery will shut off when it drops too low. as all others i have does. |
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Grinner
Registered User Joined: 02 December 2005 Location: essex Status: Offline Points: 407 |
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besides that, and thinking i am ignorant of such things.
i was making the point about the output power staying stable. even with the input voltage dipping wildly. |
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