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Chinese Hiland 0-30V/Audioguru PSU build (down the rabbit hole)
- Thread starter bushtech
- Start date
Ah! I found the instructions online:
is it ok to use the shared power supply for the time being? I know it causes a lot of interference but it will help for the time being until I can figure out seperate supply
Just thinking aloud now: 2 x 18650's in series will give about 9V. I assume this display does not use a lot of power so they should last awhile?
is it ok to use the shared power supply for the time being? I know it causes a lot of interference but it will help for the time being until I can figure out seperate supply
Just thinking aloud now: 2 x 18650's in series will give about 9V. I assume this display does not use a lot of power so they should last awhile?
The wiring diagrams look confusing. Why do Chinese people call a wire a "line"?
The yellow wire measures the positive voltage and the current is measured in series with the negative of the power supply and the negative of the load (but why with a red wire?).
I don't know if the display uses many LEDs for high current or an LCD for very low current. if you use 2 x 18650 then you will need a balanced Lithium charger.
The yellow wire measures the positive voltage and the current is measured in series with the negative of the power supply and the negative of the load (but why with a red wire?).
I don't know if the display uses many LEDs for high current or an LCD for very low current. if you use 2 x 18650 then you will need a balanced Lithium charger.
Yes the display has about 46 LEDs and each LED uses about 5mA -10mA of current.
A balanced charger adjusts the charging voltage on each cell so that the weakest one does not over-charge and blow up (Lithium is combustible when over-charged). Here is what happens if you buy a cheap Chinese Lithium 18650 cell on ebay:
A balanced charger adjusts the charging voltage on each cell so that the weakest one does not over-charge and blow up (Lithium is combustible when over-charged). Here is what happens if you buy a cheap Chinese Lithium 18650 cell on ebay:
@Audioguru: Well, the power supply is starting to work after a fashion, obeys Ohm's law. If I push out 20V into a 20Ω resistance I get 1Amp current.
However only 1 2N3055 is getting warm. Should they both be getting about equally warm?
However only 1 2N3055 is getting warm. Should they both be getting about equally warm?
Sir bushmeister . . . .et . . . .Uncle Donald . . . . . ? ? ? ? or is that Scrooge ? ? ? ? ? my childhood and
G-G Grandchildren are too far away.
Q2 is a driver for the load sharing Q4 and Q6 pair, so it might be the warm one, of the 3 . . .'3055's..
Back on your Li ions references, you were giving too much voltage output credit / capability for a series pair.
A cell, just off the charger shouldn't be over 4.25 VDC max.
Pity the meter wasn't using LCD technology, but guess that existent LED's are getting cheeeeeep to buy for the meter makers.
G-G Grandchildren are too far away.
Q2 is a driver for the load sharing Q4 and Q6 pair, so it might be the warm one, of the 3 . . .'3055's..
Back on your Li ions references, you were giving too much voltage output credit / capability for a series pair.
A cell, just off the charger shouldn't be over 4.25 VDC max.
Pity the meter wasn't using LCD technology, but guess that existent LED's are getting cheeeeeep to buy for the meter makers.
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I was just using your page one schematic, where a 3055 was used as driver.
So . . . . . .measure the DC voltage across the emitter resistors to see how well balanced the voltages are.
Or if no voltage is on one of them, your whole load might be carried by the hot one with the cold one being bad or having dodgy interconnective wiring.
So . . . . . .measure the DC voltage across the emitter resistors to see how well balanced the voltages are.
Or if no voltage is on one of them, your whole load might be carried by the hot one with the cold one being bad or having dodgy interconnective wiring.
Was busy typing this when you posted. Still a bit puzzled by the one 3055 running much hotter than the other (Have measured the voltages at both resistors after the 3055's and they are the same.) The second 3055 is warming up slightly. Am I right in saying that the matching of those 2 resistors (0.33Ω) is responsible for making the 2 3055's work equally hard.
My two resistors both read 0.6Ω on my DMM. I don't think it can reliably read that low. One is a carbon resistor and the other is a metal film one. Cause a difference?
My two resistors both read 0.6Ω on my DMM. I don't think it can reliably read that low. One is a carbon resistor and the other is a metal film one. Cause a difference?
One 2N3055 is mounted beside the bridge rectifier and the BD139 making it hotter than the 2N3055 transistor by itself?
Measure the resistance of the leads on your multimeter and subtract its resistance from the 0.6 ohms you measure for each resistor. I had a meter that did that calculation when I touched the probes together.
You might have a 2N3055 with no gain or with its collector disconnected and it has a massive base current.
Measure the resistance of the leads on your multimeter and subtract its resistance from the 0.6 ohms you measure for each resistor. I had a meter that did that calculation when I touched the probes together.
You might have a 2N3055 with no gain or with its collector disconnected and it has a massive base current.
Thanks Audioguru. I managed to sort it. The problem was not the cold one but the hot one, One of the bolts bolting the 3055 down was not quite tight causing improper heat transfer ergo hot 2N3055. Nipped it down and the 2 power transistors now about equal heat wise.
Thanks for that headsup on the leads resistance. Measured that at 0.5Ω. So 0.6-0.5=1Ω which is as close as I am going to get to 0.33Ω on my meter.
Thanks again for the patient help
Thanks for that headsup on the leads resistance. Measured that at 0.5Ω. So 0.6-0.5=1Ω which is as close as I am going to get to 0.33Ω on my meter.
Thanks again for the patient help
Starting to look at another display for the power supply. Your statement:" I don't know if the display uses many LEDs for high current or an LCD for very low current." got me thinking.
How about an lcd display like this:
Link here: https://www.banggood.com/PZEM-031-D...-p-1111791.html?rmmds=search&cur_warehouse=CN
Does this draw appreciably lower current?
How about an lcd display like this:
Link here: https://www.banggood.com/PZEM-031-D...-p-1111791.html?rmmds=search&cur_warehouse=CNDoes this draw appreciably lower current?
An LCD display draws very little current (used in a watch powered continuously for months from a button battery) but it has a few LEDs that use some current. The Banggood display is powered from the voltage it is measuring so its minimum supply is 6.5V. Banggood, ebay and Amazon all had their copy of the original defective Greek kit and have replaced it with a power supply with poor specs but it has a display. Maybe they sell the display separately.
Thanks Audioguru.
Had a look on banggood but the one with the display uses 2 pcb's with interconnecting 5 core ribbon. So doubt that I could hack it even if I could get the display separately.
But I found this: OLED display and goes down to 0V
https://www.banggood.com/100V20A-7i...s=detail-left-viewhistory__3&cur_warehouse=CN
I think this will work
Had a look on banggood but the one with the display uses 2 pcb's with interconnecting 5 core ribbon. So doubt that I could hack it even if I could get the display separately.
But I found this: OLED display and goes down to 0V
https://www.banggood.com/100V20A-7i...s=detail-left-viewhistory__3&cur_warehouse=CN
I think this will work
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