Hello,

I would like to use an Ac-5dc module PBO-5C-5 to deliver at the most 20-100mA for mcu signalling only. my intention is to use the minimum necessary peripherials (C1,CY1,L1 ets'), my question is: can i use this module for my purposes (max 5vdc 100mA) witout using the capacitors as suggested in the data sheet?

This module feeds from Ac line in the circuit after it passed an AC 0.1uF and 2 varistors and on the 5vdc output i added 1uf + 0.1uf.

Thanks

 

I appreciate your goal of minimizing size but the datasheet lists the caps as “required” if they weren’t why would that be the case? The manufacturer would certainly omit those parts to reduce the BoM for competitive reasons if it was possible.

Those capacitors are absolutely necessary for filtering, the stability of the converter may also be compromised without them. If you breadboard the IC without the caps and check the output on a scope, it will be extremely obvious why they are needed.

 

Hi Yaakov, Well noted and Thank you for your reply. Byd, is C1 noted for 22uF 450VAC?

As to that, i might need to find other solution.

Can you Advice if you have any other idea for delivering 230VAC to 5VDC @Max only 100mA? (i thought of maybe via bridge rectifier diodes to 4 resistors in series and zener diode?)

 

Hi Yaakov, Well noted and Thank you for your reply. Byd, is C1 noted for 22uF 450VAC?

As to that, i might need to find other solution.

Can you Advice if you have any other idea for delivering 230VAC to 5VDC @Max only 100mA? (i thought of maybe via bridge rectifier diodes to 4 resistors in series and zener diode?)

You will not be able to avoid capacitors. If you omit them in any solution the DC will be basically half an AC waveform.

The high voltage capacitors specified in the datasheet are ones that deal with the line voltage so they have to be capable of dealing with the RMS voltage after rectification. CY1 must be a class Y capacitor because if it fails in a short circuit it will cause a lot of magic smoke to escape and/or possible cause a very unpleasant electrical experience for an unsuspecting human. Class Y capacitors are designed to fail open.

In general, trying to work with mains voltages—particularly ~240V—in a very small space is extremely difficult to do safely, If you can use a commercial solution with all of its safety components, you need to find more space. Bear in mind you also need anti-tracking slots to prevent arc-over. These are not optional.

 

Thanks

 

Can you Advice if you have any other idea for delivering 230VAC to 5VDC @Max only 100mA? (i thought of maybe via bridge rectifier diodes to 4 resistors in series and zener diode?)

Many options available but trying to do your own in discrete parts isn't a good idea - you need the isolation of a switch-mode supply.

Also, whichever product you decide to use do not omit the recommended fuse and MOV at input, nor the recommended
isolation slots between AC and DC pins - they are not there for fun.

I often use, and recommend, the RECOM series of encapsulated AC/DC converters, the RAC01-05SC gives 1W output (5v/200mA) and needs an optional 330uF capacitor on the output for <100mV ripple, or leave it off if you can accept ~200mV ripple.

Data-sheet here: https://docs.rs-online.com/9163/0900766b8135f263.pdf



Another similar, but slightly cheaper, option is the MEANWELL IRM-01-5 5v/1W (link to data-sheet). Needs 47u and 0.1u on output to meet <150mV ripple spec and is very good (on paper) for regulation

Also, RECOM RAC01-5SGB, also 5v/200mA and cheaper. but isn't as good as its more expensive brother on voltage accuracy, but good enough for many peripherals.

There are many more similar - just search Mouser or Digikey for "5v/1W ac/dc converter"

 

Hi Irving,

I found also a chinese module such as this one: HLK-2M05 5V, 0.4A for more resonable price
http://h.hlktech.com/download/ACDC电源模块2W系列/1/海凌科电子2W系列电源模块说明书V2.3.pdf

 

Hi Irving,

I found also a chinese module such as this one: HLK-2M05 5V, 0.4A for more resonable price
http://h.hlktech.com/download/ACDC电源模块2W系列/1/海凌科电子2W系列电源模块说明书V2.3.pdf

Its cheap because it doesn't have the input side common-mode choke internally, see page 6 & 7 of datasheet...

 

Its cheap because it doesn't have the input side common-mode choke internally, see page 6 & 7 of datasheet...

Hi Irvin,

Well noted, i would like to use this 5v module HLK-2M05 and the noted choke should be 10mH as in their design attched. i also found 3 that might be relevant, Can you please take a look to see if they can fit? (in my location needed AC 220V, 50Hz)

T98-103MLN - in this one its noted As min 8mH, can this have any stability affect?

UU9.8-10mH
UU10.5Y-10mH

Thanks

 

Hi Irvin,

Well noted, i would like to use this 5v module HLK-2M05 and the noted choke should be 10mH as in their design attched. i also found 3 that might be relevant, Can you please take a look to see if they can fit? (in my location needed AC 220V, 50Hz)

Any of these will work, though they are quite large compared to the module. I can't tell you if they will physically fit your location, they are between 1/2 and 2/3 the volume of the converter so physically the overall end result is much bigger than the modules I suggested and you have to make the connections. Nor do I know any of these manufacturers so can't comment on the quality/reliability. How many are you looking to purchase?

#1 T98-103MLN - in this one its noted As min 8mH, can this have any stability affect?

No, the minimum value is not an issue, though the others claim a better tolerance. This is the only one to specify the rated max operating current at 700mA, but that's much more than needed so OK. Depending on price this is the one I'd go for...

#2 UU9.8-10mH

This is the same size core as above, but wound with more turns of a thinner wire (75 x 0.2mm v 65 x 0.3mm) and so has a higher resistance at 1.2Ω (v 0.7Ω max, 0.5Ω typical) and will have a lower max operating current. Not necessarily an issue

#3 UU10.5Y-10mH

Physically bigger core than #1 & #2 but otherwise identical winding to #1 though again no current spec. No real benefit in choosing this one unless significantly cheaper and you have the space for it.

 

Any of these will work, though they are quite large compared to the module. I can't tell you if they will physically fit your location, they are between 1/2 and 2/3 the volume of the converter so physically the overall end result is much bigger than the modules I suggested and you have to make the connections. Nor do I know any of these manufacturers so can't comment on the quality/reliability. How many are you looking to purchase?

#1 T98-103MLN - in this one its noted As min 8mH, can this have any stability affect?

No, the minimum value is not an issue, though the others claim a better tolerance. This is the only one to specify the rated max operating current at 700mA, but that's much more than needed so OK. Depending on price this is the one I'd go for...

#2 UU9.8-10mH

This is the same size core as above, but wound with more turns of a thinner wire (75 x 0.2mm v 65 x 0.3mm) and so has a higher resistance at 1.2Ω (v 0.7Ω max, 0.5Ω typical) and will have a lower max operating current. Not necessarily an issue

#3 UU10.5Y-10mH

Physically bigger core than #1 & #2 but otherwise identical winding to #1 though again no current spec. No real benefit in choosing this one unless significantly cheaper and you have the space for it.

Irvin,

Well noted and Thank you for your Assistance. will have to order and test it.