I have started construction of a 6 channel battery powered system (16S, 20Ah lithium ion) and have some TPA3251 based amplifiers from 3e audio on the way as a starting point. A buck converter is used between the battery and the amps to supply their 36V supply.
If this works out well though its likely that I would want considerably more power for subs than the TPA3251 can supply, I am aware of the TPA3255 which would run off a 51V supply (it was out of stock and has higher idle power consumption so I decided to go with the TPA3251 for now), what options are available for higher powered single supply amplifier modules?
I looked at sure electronics/wondom and their higher powered modules (up to 3000W) all seemed to require split supplies.
I'm not interested in amplifiers that can drive ultra low impedance to get their power rating (typical car audio amplifier) as pro audio drivers are only available in 8 or 4 ohms so to get good volumetric efficiency from the system the amplifier should develop maximum power into 4 ohm.
If this works out well though its likely that I would want considerably more power for subs than the TPA3251 can supply, I am aware of the TPA3255 which would run off a 51V supply (it was out of stock and has higher idle power consumption so I decided to go with the TPA3251 for now), what options are available for higher powered single supply amplifier modules?
I looked at sure electronics/wondom and their higher powered modules (up to 3000W) all seemed to require split supplies.
I'm not interested in amplifiers that can drive ultra low impedance to get their power rating (typical car audio amplifier) as pro audio drivers are only available in 8 or 4 ohms so to get good volumetric efficiency from the system the amplifier should develop maximum power into 4 ohm.
further browsing of the Wondom store and I found this:
WONDOM | STORE
up to 136V supply, perhaps a winner? although I'm a bit confused at the 2*900W into 6 ohm rating as the supply voltage suggests much more power should be available.
WONDOM | STORE
up to 136V supply, perhaps a winner? although I'm a bit confused at the 2*900W into 6 ohm rating as the supply voltage suggests much more power should be available.
Would you use batteries to supply +136V ?
Most people would have gone down the SMPS route.
An SMPS supply can provide any voltage that you require from a battery source.
Most people would have gone down the SMPS route.
An SMPS supply can provide any voltage that you require from a battery source.
I have a buck converter at the moment making 36V from the nominal 64V pack but making +/- rails (although perfectly possible) has less off the shelf electronics to do it so would involve significant time investment in designing my own power converter or something hacky like using two isolated boost converters.
For a higher power amp I would run it direct from the pack or use a boost converter. I could even make a new pack at higher nominal voltage. It depends greatly on how the current system performs as I am unsure of real world run time with my 1.18kWh pack. Essentially my current system is a proof of concept and I just want to know my options with regard to higher power amplifiers.
For a higher power amp I would run it direct from the pack or use a boost converter. I could even make a new pack at higher nominal voltage. It depends greatly on how the current system performs as I am unsure of real world run time with my 1.18kWh pack. Essentially my current system is a proof of concept and I just want to know my options with regard to higher power amplifiers.
yep but so does an amplifier running in bridge tied load mode which is also good for getting double the voltage swing across the speaker for a given DC bus voltage. Also found this 2500W rated module:
WONDOM | STORE
a bit expensive for what it is and idle power consumption of 25W is not fantastic. Switching frequency is 400 kHz which is probably responsible for most of that, I would accept larger passives to switch slower for an amp of this power rating.
WONDOM | STORE
a bit expensive for what it is and idle power consumption of 25W is not fantastic. Switching frequency is 400 kHz which is probably responsible for most of that, I would accept larger passives to switch slower for an amp of this power rating.
Possibly because of the high switching frequency of 550kHz? Or the heat-sinking constraints?
Probably isolated full bridge converter, if you look at figure 1:
https://www.ti.com/lit/ug/tidu248/tidu248.pdf
you can see that by altering the secondary side circuit that you can generate a negative voltage as well as positive. Limitation been that regulation will have to be sensed from one rail so asymmetrical loading should be avoided.
The main reason I don't want to go with a custom SMPS generating split rails is that it would be quite a lot of effort and time while hooking up a single supply amplifier would be easier. Infact it would be easier to design my own amp that single supply and low power consumption than a decent SMPS. My nominal battery voltage is 64V so potentially a directly connected full bridge amp could get close to 500W into 4 ohms.
What the world needs is a good tack-on class-d power booster.
Take any class-d amp that can drive at least 3.3V logic levels - hook this thing onto it in the proper place - and you're only limited by the voltage, current specs of the output FETs and inductors you choose to build it with - not what some manufacturer thought would be a good, all around solution for portable audio.
Take any class-d amp that can drive at least 3.3V logic levels - hook this thing onto it in the proper place - and you're only limited by the voltage, current specs of the output FETs and inductors you choose to build it with - not what some manufacturer thought would be a good, all around solution for portable audio.
1. A synchronous buck converter can sink as well as supply a voltage so you could buck your 64V into +/-32V.
2. If the amp input references a divider instead of "ground" then it can be used to create it's own ground, something like a capacitor output but with a pair of caps (in series) in the speaker return connected to +V and -V.
3. You can use a voltage inverting or isolated DC-DC converter to create +/-64VDC, ie convert one side only.
4. Most practically, Most class-D chips use a bridge so a single supply is fine. You may want to re-wire your 64V 20Ah into 32V 40Ah, or two 32V 20Ah for two channels.
2. If the amp input references a divider instead of "ground" then it can be used to create it's own ground, something like a capacitor output but with a pair of caps (in series) in the speaker return connected to +V and -V.
3. You can use a voltage inverting or isolated DC-DC converter to create +/-64VDC, ie convert one side only.
4. Most practically, Most class-D chips use a bridge so a single supply is fine. You may want to re-wire your 64V 20Ah into 32V 40Ah, or two 32V 20Ah for two channels.
