I'm pretty much a total noob to electronics, and seem to be in way over my head trying to complete a project. I'm planning on using two peltier devices (Vmax 15.6V, Imax =26A) as my heat pump for a cooling/sometimes heating application. I've done way more research than i was anctipating I was going to need to, and still feel like I really have no idea whats going on.
I picked up two meanwell 15V DC power supplies rated for 20A, and Im hoping to wire each peliter separately with a power supply and use a microcontroller to control the voltage they see with PWM. I tried to figure out wiring the supplies in parallel as well we as the peltiers, but it seems like that would be the much more complicated route.
One of these peltier circuits will be designed to heat and cool with an H-bridge (still muddling through picking parts), while the other will be designed to cool only. An FAQ from a TEC manufacturer suggests that if you used PWM to keep voltage ripple to less than 10% for best performance and longevity. So my goal is to design filters to give me 10% voltage ripple or less at a 50% duty cycle if I'm using a 20kHz signal from an Arduino.
From my what I think I've pieced together I think I figured out how to design a low pass RC low pass filter (cutoff freq around 2kHz). But given the current I'd be working with adding a resistor will waste alot of power.
So it seems like I need an LC low pass filter, but I’m having a hard time finding good web resources on this as most of them are for AC power and radio design. With my spotty understanding I took a stab at sizing an inductor and it looks for the size I’d need (on the order of 10's of micro-henries) for the current it needs to handle they will be expensive. If I need 3 of them (one of them to filter cooling in the h-bridge, one of them for heating in the h-bridge and one of them for cooling-only circuit) then filtering may start to get components may start to get prohibitively expensive for this approach.
I could seriously use help, I'm pretty lost here. I know there is alot I need to learn, but this is getting really overwhelming for what I was hopping would be a pretty simple project. Any help with sizing an LC filter would be really appreciated. I could also potentially change out peltiers for higher voltage (Vmax 31.5V, Imax 17A), can I make this work with my power supplies and would it simplify the filter situation?
thanks in advance
I picked up two meanwell 15V DC power supplies rated for 20A, and Im hoping to wire each peliter separately with a power supply and use a microcontroller to control the voltage they see with PWM. I tried to figure out wiring the supplies in parallel as well we as the peltiers, but it seems like that would be the much more complicated route.
One of these peltier circuits will be designed to heat and cool with an H-bridge (still muddling through picking parts), while the other will be designed to cool only. An FAQ from a TEC manufacturer suggests that if you used PWM to keep voltage ripple to less than 10% for best performance and longevity. So my goal is to design filters to give me 10% voltage ripple or less at a 50% duty cycle if I'm using a 20kHz signal from an Arduino.
From my what I think I've pieced together I think I figured out how to design a low pass RC low pass filter (cutoff freq around 2kHz). But given the current I'd be working with adding a resistor will waste alot of power.
So it seems like I need an LC low pass filter, but I’m having a hard time finding good web resources on this as most of them are for AC power and radio design. With my spotty understanding I took a stab at sizing an inductor and it looks for the size I’d need (on the order of 10's of micro-henries) for the current it needs to handle they will be expensive. If I need 3 of them (one of them to filter cooling in the h-bridge, one of them for heating in the h-bridge and one of them for cooling-only circuit) then filtering may start to get components may start to get prohibitively expensive for this approach.
I could seriously use help, I'm pretty lost here. I know there is alot I need to learn, but this is getting really overwhelming for what I was hopping would be a pretty simple project. Any help with sizing an LC filter would be really appreciated. I could also potentially change out peltiers for higher voltage (Vmax 31.5V, Imax 17A), can I make this work with my power supplies and would it simplify the filter situation?
thanks in advance
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