so being a bumbling DIY fan has its drawbacks. i fried a chip amp board last night, probably cuz i used an AC switch instead of a DC switch. would have been no problem if i had remembered to use a fuse...
would like some help confirming my post mortem and choice of solutions!
i am playing with a TI TPA 3250 evaluation board. http://www.ti.com/tool/tpa3250d2evm it is a step up in power from the TPA 3116 chip amps that a lot of DIYers have been playing with (huge thread on AK as well as on audiocircle and DIYaudio). however, it needs a bigger power supply. instead of using a switching power supply (may hurt the sonics), i've tried a battery set up:
http://audiokarma.org/forums/index.php?threads/tpa-3116-vs-the-tripaths.574806/page-287 (see post 5726)
three 12 volt batteries in series (36 volts) gets me into the power supply range the chip needs -- 5–14 A/18–38 VDC. users guide: http://www.ti.com/lit/ug/slvuam9/slvuam9.pdf (see 2.2).
i wanted to put it into a case that has an on/off switch. not realizing there are AC and DC switches i bought an AC switch. http://www.parts-express.com/spst-heavy-duty-toggle-switch-with-screw-terminals--060-370 (i had learned earlier that battery power is DC.) here are some pics of my case showing the wiring: http://albums.phanfare.com/isolated/VZi5sXAT/1/14440191
stupidly, i did not include a fuse... when i hooked it up to the batteries and flipped the switch all HELL broke loose. the chip started smoking and then the large caps literally blew their tops. wish i had it on video.
i am pretty confident i have the batteries wired in series correctly. i also think i wired the switch properly (except no fuse)
so what next? i ordered a new board (luckily they are still on 1/2 off sale) and a DC switch: https://www.amazon.com/gp/product/B002MJBQKK/ref=od_aui_detailpages00?ie=UTF8&psc=1
it is rated for 10 amps at 36 volts DC.
questions:
1. is the switch my real problem?
2. if yes, will this DC switch be adequate?
3. how big a fuse do i need?
thanks!
would like some help confirming my post mortem and choice of solutions!
i am playing with a TI TPA 3250 evaluation board. http://www.ti.com/tool/tpa3250d2evm it is a step up in power from the TPA 3116 chip amps that a lot of DIYers have been playing with (huge thread on AK as well as on audiocircle and DIYaudio). however, it needs a bigger power supply. instead of using a switching power supply (may hurt the sonics), i've tried a battery set up:
http://audiokarma.org/forums/index.php?threads/tpa-3116-vs-the-tripaths.574806/page-287 (see post 5726)
three 12 volt batteries in series (36 volts) gets me into the power supply range the chip needs -- 5–14 A/18–38 VDC. users guide: http://www.ti.com/lit/ug/slvuam9/slvuam9.pdf (see 2.2).
i wanted to put it into a case that has an on/off switch. not realizing there are AC and DC switches i bought an AC switch. http://www.parts-express.com/spst-heavy-duty-toggle-switch-with-screw-terminals--060-370 (i had learned earlier that battery power is DC.) here are some pics of my case showing the wiring: http://albums.phanfare.com/isolated/VZi5sXAT/1/14440191
stupidly, i did not include a fuse... when i hooked it up to the batteries and flipped the switch all HELL broke loose. the chip started smoking and then the large caps literally blew their tops. wish i had it on video.
i am pretty confident i have the batteries wired in series correctly. i also think i wired the switch properly (except no fuse)
so what next? i ordered a new board (luckily they are still on 1/2 off sale) and a DC switch: https://www.amazon.com/gp/product/B002MJBQKK/ref=od_aui_detailpages00?ie=UTF8&psc=1
it is rated for 10 amps at 36 volts DC.
questions:
1. is the switch my real problem?
2. if yes, will this DC switch be adequate?
3. how big a fuse do i need?
thanks!