Totally confused about power supplies

[IPunchCholla]

Ok. I’m considering DIYing an amp (based on the TDA7294). I’m looking for a power supply I can run external initially while I test it out (Figuring I would build one channel and once I have confirmed the heat and power characteristics build the second and get a finished case). Basically I just want to buy a power supply rather than build one. But I’m confused by the available supplies on Mouser and Digikey. I was looking at the Meanwells in the 300 watt, 24 to 36v range. But I can’t figure out what the -V pins are referenced to. Are these +-24V (or +-36) power supplies? I guess I’m wondering if there are any good articles on understanding power supplies in terms of the info listed in the specs. I mean I’ve read up on the SMPS and linear supplies and I get them enough to model simple linear supplies, but apparently not enough to know what I am buying wil work (except the Connex and Hypex ones). I’m clearly missing something. Anyway here is a link to the SMPS I was trying to figure out.

 

[DVDdoug]

There may be a common (probably NOT permanently wired to chassis ground) or sometimes there are two (or more) isolated outputs (4 terminals for a dual power supply). If they are isolated can connect the + output of one "channel" to the - output of the other "channel" and that's your common which you can optionally ground.

If it's not clear on the datasheet it should be obvious when you get it in your hands and you can see the terminals.

 

[restorer-john]

The unit you have linked is a single ended supply (variable between 32.4 to 39.4V). The gnd pin is chassis earth, the L and N self explanatory and the + and - terminals are just multiple connection points for each.

The TDA-7294 runs on a dual (+/- rails) supply. In other words, a + voltage, a zero common and a negative voltage. e.g 36-0-36V.

The supply you have linked is not suitable.

Edit: You could use that single ended supply if you were using two TDA-7294s in bridge tied load configuration.

 

[Laotze]

My advice is to get a SPICE program and start playing. You can learn, quite quickly, to make a power supply in a program like multisim, it's fast, fun, and you will probably learn quite a bit in the process. You can then simulate the rest of your design too.

 

[IPunchCholla]

My advice is to get a SPICE program and start playing. You can learn, quite quickly, to make a power supply in a program like multisim, it's fast, fun, and you will probably learn quite a bit in the process. You can then simulate the rest of your design too.

I’ve been building circuits in Fusion 360 and iCircuit designer. But haven’t leveraged spice for Fusion 360. I’ll check out multisim! I’ve built a linear supply in iCircuit but I would rather just buy a supply, particularly as I would rather use a SMPS. I’ll probably just go with the Connex SMPS500R or 300R

 

[Laotze]

I've used Fusion 360 and
Inventor for cad/cam extensively. I haven't looked at the other functionality, if it has an ok catalogue of parts it should be a perfectly fine program to use.

I really like the simulated instruments that are in multisim though. You can attach a simulated signal generator and oscilloscope to get a really good idea of what is going on at every point in the circuit.

When I first started playing I learnt a fair amount about eliminating ripple with capacitors, capacitance multipliers, chokes, etc. And also how to do it safely.

 

[IPunchCholla]

I've used Fusion 360 and
Inventor for cad/cam extensively. I haven't looked at the other functionality, if it has an ok catalogue of parts it should be a perfectly fine program to use.

I really like the simulated instruments that are in multisim though. You can attach a simulated signal generator and oscilloscope to get a really good idea of what is going on at every point in the circuit.

When I first started playing I learnt a fair amount about eliminating ripple with capacitors, capacitance multipliers, chokes, etc. And also how to do it safely.

The parts library is pretty weak in Fusion 360. Which why I haven’t be doing any simulation in it. But you can download spice models and add them to your circuits. The process doesn’t look easy though, which is why I haven’t done it yet. I did look at Multisim and it looks much better. I’ll start playin around with the free version.