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The STM voltage regulator on the Raduino board gets really hot. Is that normal?
also, it sticks out and i’d Like to bend it back so my display panel fits in my box. No issue bending it (carefully), right?
thx
paul
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Why not add a heat sink if not already done?
?Secondly you mught fix the regulator on the metal enclosure body, if you used one.and extend wires to the raduino pcb. ?I dont recollect whetyher the backlit isat 5V? !!? I generally separate it out and connect to 12V with 1 watt higher value resistor like 560 ohms. Tothat extent, the load is reduced on the regulator. all the best ?sarma ?vu3zmv
On Fri, Oct 6, 2017 at 9:33 AM, Paul Avona via Groups.Io <avonap@...> wrote: The STM voltage regulator on the Raduino board gets really hot. Is that normal?
also, it sticks out and i’d Like to bend it back so my display panel fits in my box. No issue bending it (carefully), right?
thx
paul
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On Thu, Oct 5, 2017 at 09:03 pm, Paul Avona wrote:
The STM voltage regulator on the Raduino board gets really hot. Is that normal?
also, it sticks out and i’d Like to bend it back so my display panel fits in my box. No issue bending it (carefully), right?
thx
paul
As I recall, I removed mine, turned it around, then laid it down flat. Here's a picture:  ? -- John - WA2FZW
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In the pjhotoabove , i suggest the regulator be mounted physically on the marked location in the attachment, and wires extended to the PCB.
?It helps.
On Fri, Oct 6, 2017 at 10:20 AM, John P <j.m.price@...> wrote: On Thu, Oct 5, 2017 at 09:03 pm, Paul Avona wrote:
The STM voltage regulator on the Raduino board gets really hot. Is that normal?
also, it sticks out and i’d Like to bend it back so my display panel fits in my box. No issue bending it (carefully), right?
thx
paul
As I recall, I removed mine, turned it around, then laid it down flat. Here's a picture:
?
--
John - WA2FZW
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Comparatively, the 7805 is like a dropping resistor. You're taking 12 -14 volts and regulating it to 5 volts. That's a 7 volt drop, which at 1 amp would be:
(InputVoltage - OutputVoltage)* Current Supplied = (12-5) * 1 = 7W
If you compare that to a resistor, you can see that a LDO is not very efficient when compared to a switching regulator. If you use a switching regulator, there are problems associated with RFI to deal with.
Use a heat sink or bolt it to a metal chassis.
On Friday, October 6, 2017 12:03 AM, Paul Avona via Groups.Io <avonap@...> wrote:
The STM voltage regulator on the Raduino board gets really hot. Is that normal?
also, it sticks out and i’d Like to bend it back so my display panel fits in my box. No issue bending it (carefully), right?
thx
paul
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On Thu, Oct 5, 2017 at 10:08 pm, Mvs Sarma wrote:
In the pjhotoabove , i suggest the regulator be mounted physically on the marked location in the attachment, and wires extended to the PCB.
Like they say "If it ain't broke, don't fix it!" Mine isn't?getting all that hot, so I'm not going to worry about it. My box does have a fan also, BTW. ? -- John - WA2FZW
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The 5 V regulator on my raduino runs cool. ?My raduino, including the LCD display, draws 76 mA at supply voltages from 8-12 volts. ?Where is all your current going? ?I removed the regulator and reinstalled it on the side of the board where the connctors attach.
Ben - K0IKR
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yes...it DOES get hot.? put a small heatsink on it.? One of the issues is that it is the backlite for the LCD is connected to it. You can try changing out the series resistor for the backlite on the LCD to dim it down thus reducing the load or cut the trace and run dedicated power to it.
On Sun, Oct 8, 2017 at 11:59 AM, Ben Bangerter, K0IKR via Groups.Io <bwbangerter@...> wrote: The 5 V regulator on my raduino runs cool.? My raduino, including the LCD display, draws 76 mA at supply voltages from 8-12 volts.? Where is all your current going?? I removed the regulator and reinstalled it on the side of the board where the connctors attach.
Ben - K0IKR
-- Paul Mateer, AA9GG
Elan Engineering Corp.
NAQCC 3123, SKCC 4628
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Re: LED Backlight ... It's 2 LEDs in series, the series resistor is marked 111, which I presume to be 110 ohms. Given the typical LED drops 1.3V when conducting, and supply is 5V,? I = E / R = (5-2.6) / 110 = 2.4/110 = 21.8mA. Do you really think this contributes much to the heating of the 7805?
OK, cut the track, but put in a pot (1K?) and you've got control of the light output - handy for night-ops. :)
73... Dex, ZL2DEX
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yup...it does!? I also added the external resistor
On Mon, Oct 9, 2017 at 11:57 PM, Dexter N Muir <dexy@...> wrote: Re: LED Backlight ... It's 2 LEDs in series, the series resistor is marked 111, which I presume to be 110 ohms. Given the typical LED drops 1.3V when conducting, and supply is 5V,? I = E / R = (5-2.6) / 110 = 2.4/110 = 21.8mA. Do you really think this contributes much to the heating of the 7805?
OK, cut the track, but put in a pot (1K?) and you've got control of the light output - handy for night-ops. :)
73... Dex, ZL2DEX
-- Paul Mateer, AA9GG
Elan Engineering Corp.
NAQCC 3123, SKCC 4628
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My approach is to add a 7808 regulator at the power input, so the voltage drop is in two stages.? This would feed only the "12V" input to the main circuit.? The "PA12"
would still be fed from the power supply input.
73,? Graham ZL3GSL
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Move the 7805 to the back of the PCB.
Add 47 Ohm and a bypass cap to the front of the
regulator.
I have done this on my RaduinoX PCB, as well as
Bolting the regulator to a ground heat sink with a 6-32 screw in
nut.
No heat problem after that.? No need for another
regulator.
This should have been done originally.
Here is a picture of RaduinoX.? Many problems
Fixed.? USB on the other side.? More connectors.
Mike, WA6ISP
My approach is to
add a 7808 regulator at the power input, so the voltage drop is in
two stages.? This would feed only the "12V" input to the main
circuit.? The "PA12"
would still be fed from the power supply input.
73,? Graham ZL3GSL
--
Mike Hagen, WA6ISP
10917 Bryant Street
Yucaipa, Ca. 92399
(909) 918-0058
PayPal ID "MotDog@..."
Mike@...
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Your connector isn't soldered in.
Vince.
toggle quoted message
Show quoted text
On 10/31/2017 07:23 PM, Michael Hagen wrote: Move the 7805 to the back of the PCB.
Add 47 Ohm and a bypass cap to the front of the regulator.
I have done this on my RaduinoX PCB, as well as Bolting the regulator to
a ground heat sink with a 6-32 screw in nut.
No heat problem after that. No need for another regulator.
This should have been done originally.
Here is a picture of RaduinoX. Many problems Fixed. USB on the other
side. More connectors.
Mike, WA6ISP
On 10/31/2017 3:51 PM, zl3gsl@... wrote:
My approach is to add a 7808 regulator at the power input, so the
voltage drop is in two stages. This would feed only the "12V" input
to the main circuit. The "PA12"
would still be fed from the power supply input.
73, Graham ZL3GSL --
Mike Hagen, WA6ISP
10917 Bryant Street
Yucaipa, Ca. 92399
(909) 918-0058
PayPal ID "MotDog@..."
Mike@...
--
Michigan VHF Corp.
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I did that for 'tuning clicks'. 220uF *just* did the job - I'd recommend 470 or more. My original (banjaxed) raduino was drawing excessive current, though still under 1A, so my 47E was 2W (what was to hand). My new (un-modded) raduino runs cool anyway, but I left the R and C in place - insurance? Swap sides for the 7805 is pretty much a given.
Mike, have you considered a 500E pot for display brightness, or a switchable resistor, in series with the (series) LEDs? The existing resistor is marked 111 - I presume 110E - so something of that order (shouldn't need to be wire-wound) would give a useful 'dimmer' for less-intrusive night-ops.
73 de ZL2DEX
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On 10/31/2017 5:34 PM, Dexter N Muir
wrote:
I did that for 'tuning clicks'. 220uF *just* did the job - I'd
recommend 470 or more. My original (banjaxed) raduino was
drawing excessive current, though still under 1A, so my 47E was
2W (what was to hand). My new (un-modded) raduino runs cool
anyway, but I left the R and C in place - insurance? Swap sides
for the 7805 is pretty much a given.
Mike, have you considered a 500E pot for display brightness, or
a switchable resistor, in series with the (series) LEDs? The
existing resistor is marked 111 - I presume 110E - so something
of that order (shouldn't need to be wire-wound) would give a
useful 'dimmer' for less-intrusive night-ops.
73 de ZL2DEX
--
Mike Hagen, WA6ISP
10917 Bryant Street
Yucaipa, Ca. 92399
(909) 918-0058
PayPal ID "MotDog@..."
Mike@...
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My PCB ( RaduinoX) has a place for a 1W resistor
to lower LCD Back light current.? It is marked "R9", but I ship
it with a shorted wire across it.
This could also be used for a switch for back
packers to turn off the Back light.
Mike, WA6ISP
?10/31/2017 5:34 PM, Dexter N Muir wrote:
I did that for 'tuning clicks'. 220uF *just* did the job - I'd
recommend 470 or more. My original (banjaxed) raduino was
drawing excessive current, though still under 1A, so my 47E was
2W (what was to hand). My new (un-modded) raduino runs cool
anyway, but I left the R and C in place - insurance? Swap sides
for the 7805 is pretty much a given.
Mike, have you considered a 500E pot for display brightness, or
a switchable resistor, in series with the (series) LEDs? The
existing resistor is marked 111 - I presume 110E - so something
of that order (shouldn't need to be wire-wound) would give a
useful 'dimmer' for less-intrusive night-ops.
73 de ZL2DEX
--
Mike Hagen, WA6ISP
10917 Bryant Street
Yucaipa, Ca. 92399
(909) 918-0058
PayPal ID "MotDog@..."
Mike@...
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Sane, Mike! Just for interest, the maths. Given each LED drops 1.3V or so and 5V supply, LED current (with your link in place) is about (5 - (2*1.3))/110 = 22mA or so, so given quiet Rx rig current of 140mA or so @ 12V supply (measured), the backlight is not all that great a drain.
73 ...
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AA9GG
