Hello,
My project design is in its final stages, but alas, I am new at this to say the least, and I'm looking for a quick fix, or any fix really. I need to find a way to charge SLA's at their ideal current, while powering an amplifier at a higher current.
Basically, I am modding a passive speaker into an active one, then fixing to my bike, but I need to get it working first.
The amp take a range of input voltage, (see specs in link); I'm aiming for 24V. To power it, I have 2X12v SLA, 10aH each, in series to get 24V DC. On battery mode, its pretty straight forward, no issues there.
The thing is, I want to be able to charge it and run it at the same time. My initial reaction was to buy a 24V power transformer AND a charger, and use a switch to shift the amp to run on the transformer, and then charge on a separate circuit. I now understand that most SLA chargers are regulated, with charging while consuming not really an issue.
This WOULD solve my problem, but at 10 aH, I would like a charger that gives around 1A at 24 V. The amplifier, on the other hand, draws a maximum power of around 120 Watts (connected to an 8 ohm speaker), with an average estimate around 90 at full volume, so I'm looking at (roughly) 3-6 amp draw at full volume (which would be a nice option to sustain while plugged in).
What I want:
When plugged in:
1. 28V DC (13.8V x 2 for SLA charge voltage) at 1A going to the batteries. I need all the perks of a regulated charge, so that I can just leave it plugged in indefinitely without damaging the batteries.
2. At least 6A at 24V (give or take a lot, can be 10-36V, higher is better actually) available for the amp.
3. Can just charge the batteries.
Here are my ideas/issues:
1. Hooking up a 4A regulated charger to the batteries, and the amp to the batteries. This seems like it will be too much current for the batteries, and not enough for the amp. These charges are also expensive/bulky.
2. Using a 1A-2A regulated charger as in 1. I (think) this will not really power the amp as much as it needs, or the amp will just suck up all the current, leaving none to charge the batteries.
3. Using an unregulated transformer, i.e. the one that comes with the amp (linked). This is fine for the amp, but I understand hooking the batteries into this circuit would be disastrous.
SPECS:
The thing is, I already have the transformer and amp listed here.
http://www.sureelectronics.net/goods.php?id=1762
So, I am thinking I can have a ciruit like this:
Note that the two switches here are the same switch (i.e. 3 way with those as two of the options)
The "thing" regulates the charge to be 1A, constant voltage, and tapers the current when the batteries are at full charge (to account for unloaded discharge). I thought maybe a solar regulator could do the trick, or something like that?
MY QUESTION:
Does anyone know of such a thing? I know this chip (http://en.wikipedia.org/wiki/LM317) has a lot of the desired qualities, but will it protect it from overcharge?
Otherwise, I could just make the "thing" in the diagram the 24V 1A charger itself (http://www.rapidonline.com/Electric...-18-0742/?source=googleps&utm_source=googleps), and hook it up to the AC source, but that would be heavier and more expensive then finding the "thing" I want.
Thoughts on the best way to do this? Any advice welcome really. Thanks a bunch!!
My project design is in its final stages, but alas, I am new at this to say the least, and I'm looking for a quick fix, or any fix really. I need to find a way to charge SLA's at their ideal current, while powering an amplifier at a higher current.
Basically, I am modding a passive speaker into an active one, then fixing to my bike, but I need to get it working first.
The amp take a range of input voltage, (see specs in link); I'm aiming for 24V. To power it, I have 2X12v SLA, 10aH each, in series to get 24V DC. On battery mode, its pretty straight forward, no issues there.
The thing is, I want to be able to charge it and run it at the same time. My initial reaction was to buy a 24V power transformer AND a charger, and use a switch to shift the amp to run on the transformer, and then charge on a separate circuit. I now understand that most SLA chargers are regulated, with charging while consuming not really an issue.
This WOULD solve my problem, but at 10 aH, I would like a charger that gives around 1A at 24 V. The amplifier, on the other hand, draws a maximum power of around 120 Watts (connected to an 8 ohm speaker), with an average estimate around 90 at full volume, so I'm looking at (roughly) 3-6 amp draw at full volume (which would be a nice option to sustain while plugged in).
What I want:
When plugged in:
1. 28V DC (13.8V x 2 for SLA charge voltage) at 1A going to the batteries. I need all the perks of a regulated charge, so that I can just leave it plugged in indefinitely without damaging the batteries.
2. At least 6A at 24V (give or take a lot, can be 10-36V, higher is better actually) available for the amp.
3. Can just charge the batteries.
Here are my ideas/issues:
1. Hooking up a 4A regulated charger to the batteries, and the amp to the batteries. This seems like it will be too much current for the batteries, and not enough for the amp. These charges are also expensive/bulky.
2. Using a 1A-2A regulated charger as in 1. I (think) this will not really power the amp as much as it needs, or the amp will just suck up all the current, leaving none to charge the batteries.
3. Using an unregulated transformer, i.e. the one that comes with the amp (linked). This is fine for the amp, but I understand hooking the batteries into this circuit would be disastrous.
SPECS:
The thing is, I already have the transformer and amp listed here.
http://www.sureelectronics.net/goods.php?id=1762
So, I am thinking I can have a ciruit like this:
Note that the two switches here are the same switch (i.e. 3 way with those as two of the options)
The "thing" regulates the charge to be 1A, constant voltage, and tapers the current when the batteries are at full charge (to account for unloaded discharge). I thought maybe a solar regulator could do the trick, or something like that?
MY QUESTION:
Does anyone know of such a thing? I know this chip (http://en.wikipedia.org/wiki/LM317) has a lot of the desired qualities, but will it protect it from overcharge?
Otherwise, I could just make the "thing" in the diagram the 24V 1A charger itself (http://www.rapidonline.com/Electric...-18-0742/?source=googleps&utm_source=googleps), and hook it up to the AC source, but that would be heavier and more expensive then finding the "thing" I want.
Thoughts on the best way to do this? Any advice welcome really. Thanks a bunch!!