L-Adapter

[wushuliu]

Great! Thanks Salas.

 

[Salas]

 

[shattered_dream]

Useful. What kind of circuit you plan to power?

A friend of mine wants to power his Humax Uhd receiver Es 160s and a cisco network switch... The cisco switch needs about 1a and the humax is not really known. Only thing he knows it's smps psu has 3.33A capability

 

[Salas]

IMO sink it seriously enough to be on the safe side.

 

[dewdrop]

Hi Salas,
I have not seen anyone (or I must have missed out) using the chassis as the sink for the D12,13,14,15, I plan to use the FFPF30UP20STU, Rectifiers FAST RECOVERY DIODE/600V 30A for a RPI 2B. Not likely to go beyond 1A as I have underclocked it.

Thoughts?

 

[Salas]

You probably don't need any kind of bridge diodes sinking for that.

 

[dewdrop]

Oh, not even on the chassis? So it will be air cooled like the UBiB 1.3?

 

[Salas]

You may cool on chassis if for more uses but for the specific application (1A computer) they will survive free to air cooling easily.

 

[dewdrop]

Got that, thanks!

 

[dewdrop]

Just curious, what current will start to require bridge / chassis sinking?

 

[Salas]

Just curious, what current will start to require bridge / chassis sinking?

Depends on the load's pattern of consumption too. How much stress it puts to the PSU's reservoir recharging process how often. A more helpful answer is when you have higher than 65C on the diodes, sink them.

 

[dewdrop]

As always, good insight!

 

[jgsneves]

Hi, guys,
For years I have been using a powerbank to feed Raspeberry Pi, as I found sonic performance MUCH better than with its original wallwart power supply. But a friend of mine has been telling me this linear power supply gave his system much better performance comparing to battery or an ifi power supply.

I do not have knowledge about electronics, so I would like to make a question, if you can help me: I was wondering if I can feed this power supply with a battery (this one, for example: Cncool 12V 12000mah lithium battery Rechargeable DC battery polymer batteria For monitor motor LED light outdoor spare Battery-in Rechargeable Batteries from Consumer Electronics on Aliexpress.com | Alibaba Group). Possible?

Thanks,
João

 

[Salas]

Hi, you can skip using a power transformer and bridge diodes in this linear supply and feed DC directly to its reservoir capacitors from an external DC source like a battery bank. Thick not longer than necessary cables from battery to the pins of first big capacitor will do. Just watch the polarity.

 

[jgsneves]

Thank you, Salas.


Do you think there is any advantage in this configuration with battery?

 

[Salas]

Well, there will be no ripple to reject so theoretically its a plus. On the other hand the battery has to be recharged. Every time it goes down to 7.5V recharge it. Because 2.5V difference from DC input to DC output is the minimum good difference in this design.

 

[jgsneves]

Sorry, Salas, but I dont understand: a 12v battery will not give 12v during all the time (95% charged or at just 10%)?


Thanks again.

 

[Salas]

Exactly. Down to 7.5V battery state is acceptable for 5V output of L Adapter you will have to remember.

 

[jgsneves]

Thanks again, Salas.

 

[dtses]

When you will double or triple the plate's surface area, plus it will be bolted to the chassis, the temperature should moderate a lot. Be generous with the plate's size. Because there are no fins.

There is a threshold in the sinking solutions after it they become saturated. When below that saturation threshold the temperature loses 10-15C kind of abruptly. Watch to have some top and bottom ventilation slots or holes in the final assembly.

what might be the optimal usage of case as a heatsink here?

1. Attach diodes and Q2 to inner sides? Forget about aluminum plate.
2. Attach them to 1cm aluminum plate and then screw it to the bottom lid?
3. Some better option?

case is 28 x 13 x 4 cm; aluminum plate is 12 x 10 x 1 cm