Temperature of 30°C is ok.
These two transformers are also ok. If you'll be facing higher temperature try to implement PCB like in the attched picture. That's why you also receive 8mm standoff which equals the thickness of aluminum block so you can create heatbridge between PCB and larger cooling surface. Bear in mind not to thighten screws too much as there might be a little difference in thickness, because of doublesided thermal adhesive tape.
I have it like this with 9VAC transformer for 5V output. I'd tested it with loads up to 400mA and it got barely warm after 2~3 hours.
Please send me again your paypal email to PM as I can't find it.
Best Regards,
Aleš
Attachments
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I've been making use of some of these excellent little regulator boards;
http://www.diyaudio.com/forums/digital-line-level/273474-best-dac-no-dac-23.html#post4380943
Ray
http://www.diyaudio.com/forums/digital-line-level/273474-best-dac-no-dac-23.html#post4380943
Ray
Nice build Ray. Is it true that best DAC is no DAC?
Best Regards,
Aleš
There's no conventional DAC involved and it sounds very good, but who knows about the 'best'. Why not try it yourself, I'll happily send you a PCB.
Ray
I am currently building LNMP preamplifier. When done I am gonna make measurements and post them here.
Best Regards,
Aleš
Based on the TPS7A4700 I build a 12V/1A power supply.
Here are some pictures and measurements I did on a HP3561A.
And the measurements:
0 - 20kHz measurement
ripple (2,4µVrms):
Noisefloor (-126dBV):
0 - 100kHz measurement
ripple (2,3µVrms):
noisefloor (-136dBV):
Here are some pictures and measurements I did on a HP3561A.
An externally hosted image should be here but it was not working when we last tested it.
An externally hosted image should be here but it was not working when we last tested it.
An externally hosted image should be here but it was not working when we last tested it.
And the measurements:
0 - 20kHz measurement
ripple (2,4µVrms):
An externally hosted image should be here but it was not working when we last tested it.
Noisefloor (-126dBV):
An externally hosted image should be here but it was not working when we last tested it.
0 - 100kHz measurement
ripple (2,3µVrms):
An externally hosted image should be here but it was not working when we last tested it.
noisefloor (-136dBV):
An externally hosted image should be here but it was not working when we last tested it.
Thanks!
I'm really curious about it because i build 2 power supplies with the TPS7A4700.
One fed with a LiPo battery and one on 220V~
Looking forward about your measurements.
Hi Ales
Does this new 3 pin regulator works well with Raspberry pi with attached DAC on it ?
How about heat...doest it require heatsink for this application ?
Hi,
I haven't tried 3pin regulator with Raspberry PI and DAC, but as long the current draw is less than 1A it will work.
You will need heatsink for this application. I would recommend you ordinary single PCB as it is much easier to implement it with heatsink.
Best Regards,
Aleš
I finished the 5V version and here are the results (50ohm load gives 100mA).
Other then Ales PCB i use a Amplimo 7,5Vdc version (30VA).
Inside
Back
Placement
Average measurements
Ripple: (~760nVrms, 0-100kHz)
Noisefloor (-122dB, 0-100kHz)
Ripple: (~560nVrms, 0-20kHz)
Noisefloor (-125dB, 0-20kHz)
Other then Ales PCB i use a Amplimo 7,5Vdc version (30VA).
Inside
An externally hosted image should be here but it was not working when we last tested it.
Back
An externally hosted image should be here but it was not working when we last tested it.
Placement
An externally hosted image should be here but it was not working when we last tested it.
Average measurements
Ripple: (~760nVrms, 0-100kHz)
An externally hosted image should be here but it was not working when we last tested it.
Noisefloor (-122dB, 0-100kHz)
An externally hosted image should be here but it was not working when we last tested it.
Ripple: (~560nVrms, 0-20kHz)
An externally hosted image should be here but it was not working when we last tested it.
Noisefloor (-125dB, 0-20kHz)
An externally hosted image should be here but it was not working when we last tested it.
Hi Eric,
thank you very much for posting measurements. These are very good results. I'll do the measurements with 500mA load current, so I could easily compare it with datasheet.
Best Regards,
Aleš
As it turns out I won't be able to easily compare regulator with datasheet as the results are not as accurate as I would like them to be. Upon all there is no difference when the probe is shorted to ground or connected to the output capacitor of TPS7A4700 PCB. I can conclude that only real measurements are from Kingpin who has smaller voltage range on his HP analyzer.
My setup is: Hantek DSO5102P <- LNMP (60dB gain) <- TPS7A4700 5V <- 10ohm resistive load.
20Mhz BW limit is on! Pk-Pk is shown is mV but you are really looking at uV.
Best Regards,
Aleš
My setup is: Hantek DSO5102P <- LNMP (60dB gain) <- TPS7A4700 5V <- 10ohm resistive load.
20Mhz BW limit is on! Pk-Pk is shown is mV but you are really looking at uV.
Best Regards,
Aleš
Attachments
hi Ales
I have connected the regulator board to a 6VAC traffo. By real time measurement I got 7.14VAC. After an hour connecting to the Pi2 the heatsink contacted to another heatsink on the bottom is 'warm' and I still can touch it. I guess it works.
Measurement also indicates 5VDC constant but sometimes fluctuate...
I have connected the regulator board to a 6VAC traffo. By real time measurement I got 7.14VAC. After an hour connecting to the Pi2 the heatsink contacted to another heatsink on the bottom is 'warm' and I still can touch it. I guess it works.
Measurement also indicates 5VDC constant but sometimes fluctuate...
Hello Ales,
I see your measurements and if i'm correct you measure at DC but you should measure at AC to measure only ripple.
Best regards,
K