Solar Charging Night Light not working...

[Jasen Betts]

On 2020-05-29, default <default@defaulter.net> wrote:

On Thu, 28 May 2020 19:29:11 -0000 (UTC), Jasen Betts
jasen@xnet.co.nz> wrote:

On 2020-05-28, default <default@defaulter.net> wrote:
On Thu, 28 May 2020 10:13:52 -0000 (UTC), Jasen Betts
jasen@xnet.co.nz> wrote:

On 2020-05-26, alberto.m.scattolo@gmail.com <alberto.m.scattolo@gmail.com> wrote:
On Tuesday, May 26, 2020 at 2:36:40 PM UTC+2, default wrote:
When you say the blocking oscillator works are you saying the light
works as long as the battery is charged, and the cell has full
sunlight on it? So the light stays on all the time and doesn\'t turn
off when there is light on the cell?

It would be better to think of it as a light detector that stops the
oscillator while the cell has light on it.

(the \"famous\" joule thief, is ancient technology from the days of
vacuum toobes)
https://en.wikipedia.org/wiki/Blocking_oscillator


Hi!

When I say \"The joule thief part works just fine\" I mean that, with a charged 1.2 AA battery, and bypassing the light detector, a 5mm blue led lights up very bright. So, the oscillator works, otherwise the led would not switch on at all.
\"Bypassing the light detector\" means that I connect the battery positive to the center of the transformer directly, without going through the first transistor so that the transformer is always powered by the battery as far as it is charged. This works with or without the solar panel, with or without light on it.

I am interested in making the light detector work, to switch on the light only when meaningful and to maintain the battery charged.

Eventually, I would also try to replace the battery with a capacitor but I am not 100% sure this is a good idea. And I would like to know the frequency of oscillation, I don\'t know if there is a practical way to calculate it, I do not an oscilloscope.

Thanks link too!

Switching the main current to the Joule Theif is probably the wrong
approach, switch the current to the base instead, that is only switch
the current that flows through the transformer branch that goes to the
base. this is a much smaller current, and so it takes less energy to
run the switch. (you can use a smaller base current to the switch)

A second problem is that the joule thief may not start automatically
when power is gradually applied. Some sort of positive feedback to
ensure that the power snaps on should help there.

How do you plan to switch only the base of the oscillator transistor?

https://www.jameco.com/Jameco/workshop/JamecoFavorites/solarled.html

the transformer has two windings, connect the other one to the supply.

The windiings have the turn on bias a well as the inductive feedback
and turn-off riding on them. The center-tap is integral to the
operation..

it\'s just a node.

There should be a way to do it: pass the AC feedback while isolating
the DC bias,

current into the base is close enough to monodirectional that it
doesn\'t matter.

but it is a little more complicated than separating the
center tap and it would take a few more components.

a capacitor across the added transistor could maybe help with charge
scavenging a little but that 1K resistor is going to slow that down
anyway.

--
Jasen.

 

[default]

On Fri, 29 May 2020 06:02:32 -0000 (UTC), Jasen Betts
<jasen@xnet.co.nz> wrote:

On 2020-05-29, default <default@defaulter.net> wrote:
On Thu, 28 May 2020 19:29:11 -0000 (UTC), Jasen Betts
jasen@xnet.co.nz> wrote:

On 2020-05-28, default <default@defaulter.net> wrote:
On Thu, 28 May 2020 10:13:52 -0000 (UTC), Jasen Betts
jasen@xnet.co.nz> wrote:

On 2020-05-26, alberto.m.scattolo@gmail.com <alberto.m.scattolo@gmail.com> wrote:
On Tuesday, May 26, 2020 at 2:36:40 PM UTC+2, default wrote:
When you say the blocking oscillator works are you saying the light
works as long as the battery is charged, and the cell has full
sunlight on it? So the light stays on all the time and doesn\'t turn
off when there is light on the cell?

It would be better to think of it as a light detector that stops the
oscillator while the cell has light on it.

(the \"famous\" joule thief, is ancient technology from the days of
vacuum toobes)
https://en.wikipedia.org/wiki/Blocking_oscillator


Hi!

When I say \"The joule thief part works just fine\" I mean that, with a charged 1.2 AA battery, and bypassing the light detector, a 5mm blue led lights up very bright. So, the oscillator works, otherwise the led would not switch on at all.
\"Bypassing the light detector\" means that I connect the battery positive to the center of the transformer directly, without going through the first transistor so that the transformer is always powered by the battery as far as it is charged. This works with or without the solar panel, with or without light on it.

I am interested in making the light detector work, to switch on the light only when meaningful and to maintain the battery charged.

Eventually, I would also try to replace the battery with a capacitor but I am not 100% sure this is a good idea. And I would like to know the frequency of oscillation, I don\'t know if there is a practical way to calculate it, I do not an oscilloscope.

Thanks link too!

Switching the main current to the Joule Theif is probably the wrong
approach, switch the current to the base instead, that is only switch
the current that flows through the transformer branch that goes to the
base. this is a much smaller current, and so it takes less energy to
run the switch. (you can use a smaller base current to the switch)

A second problem is that the joule thief may not start automatically
when power is gradually applied. Some sort of positive feedback to
ensure that the power snaps on should help there.

How do you plan to switch only the base of the oscillator transistor?

https://www.jameco.com/Jameco/workshop/JamecoFavorites/solarled.html

the transformer has two windings, connect the other one to the supply.

The windiings have the turn on bias a well as the inductive feedback
and turn-off riding on them. The center-tap is integral to the
operation..

it\'s just a node.

There should be a way to do it: pass the AC feedback while isolating
the DC bias,

current into the base is close enough to monodirectional that it
doesn\'t matter.

but it is a little more complicated than separating the
center tap and it would take a few more components.

a capacitor across the added transistor could maybe help with charge
scavenging a little but that 1K resistor is going to slow that down
anyway.

So you have... nothing. Post a schematic.

 

[default]

On Fri, 29 May 2020 06:02:32 -0000 (UTC), Jasen Betts
<jasen@xnet.co.nz> wrote:

On 2020-05-29, default <default@defaulter.net> wrote:
On Thu, 28 May 2020 19:29:11 -0000 (UTC), Jasen Betts
jasen@xnet.co.nz> wrote:

On 2020-05-28, default <default@defaulter.net> wrote:
On Thu, 28 May 2020 10:13:52 -0000 (UTC), Jasen Betts
jasen@xnet.co.nz> wrote:

On 2020-05-26, alberto.m.scattolo@gmail.com <alberto.m.scattolo@gmail.com> wrote:
On Tuesday, May 26, 2020 at 2:36:40 PM UTC+2, default wrote:
When you say the blocking oscillator works are you saying the light
works as long as the battery is charged, and the cell has full
sunlight on it? So the light stays on all the time and doesn\'t turn
off when there is light on the cell?

It would be better to think of it as a light detector that stops the
oscillator while the cell has light on it.

(the \"famous\" joule thief, is ancient technology from the days of
vacuum toobes)
https://en.wikipedia.org/wiki/Blocking_oscillator


Hi!

When I say \"The joule thief part works just fine\" I mean that, with a charged 1.2 AA battery, and bypassing the light detector, a 5mm blue led lights up very bright. So, the oscillator works, otherwise the led would not switch on at all.
\"Bypassing the light detector\" means that I connect the battery positive to the center of the transformer directly, without going through the first transistor so that the transformer is always powered by the battery as far as it is charged. This works with or without the solar panel, with or without light on it.

I am interested in making the light detector work, to switch on the light only when meaningful and to maintain the battery charged.

Eventually, I would also try to replace the battery with a capacitor but I am not 100% sure this is a good idea. And I would like to know the frequency of oscillation, I don\'t know if there is a practical way to calculate it, I do not an oscilloscope.

Thanks link too!

Switching the main current to the Joule Theif is probably the wrong
approach, switch the current to the base instead, that is only switch
the current that flows through the transformer branch that goes to the
base. this is a much smaller current, and so it takes less energy to
run the switch. (you can use a smaller base current to the switch)

A second problem is that the joule thief may not start automatically
when power is gradually applied. Some sort of positive feedback to
ensure that the power snaps on should help there.

How do you plan to switch only the base of the oscillator transistor?

https://www.jameco.com/Jameco/workshop/JamecoFavorites/solarled.html

the transformer has two windings, connect the other one to the supply.

The windiings have the turn on bias a well as the inductive feedback
and turn-off riding on them. The center-tap is integral to the
operation..

it\'s just a node.

There should be a way to do it: pass the AC feedback while isolating
the DC bias,

current into the base is close enough to monodirectional that it
doesn\'t matter.

but it is a little more complicated than separating the
center tap and it would take a few more components.

a capacitor across the added transistor could maybe help with charge
scavenging a little but that 1K resistor is going to slow that down
anyway.

So you have... nothing. Post a schematic.

 

[default]

On Fri, 29 May 2020 06:02:32 -0000 (UTC), Jasen Betts
<jasen@xnet.co.nz> wrote:

On 2020-05-29, default <default@defaulter.net> wrote:
On Thu, 28 May 2020 19:29:11 -0000 (UTC), Jasen Betts
jasen@xnet.co.nz> wrote:

On 2020-05-28, default <default@defaulter.net> wrote:
On Thu, 28 May 2020 10:13:52 -0000 (UTC), Jasen Betts
jasen@xnet.co.nz> wrote:

On 2020-05-26, alberto.m.scattolo@gmail.com <alberto.m.scattolo@gmail.com> wrote:
On Tuesday, May 26, 2020 at 2:36:40 PM UTC+2, default wrote:
When you say the blocking oscillator works are you saying the light
works as long as the battery is charged, and the cell has full
sunlight on it? So the light stays on all the time and doesn\'t turn
off when there is light on the cell?

It would be better to think of it as a light detector that stops the
oscillator while the cell has light on it.

(the \"famous\" joule thief, is ancient technology from the days of
vacuum toobes)
https://en.wikipedia.org/wiki/Blocking_oscillator


Hi!

When I say \"The joule thief part works just fine\" I mean that, with a charged 1.2 AA battery, and bypassing the light detector, a 5mm blue led lights up very bright. So, the oscillator works, otherwise the led would not switch on at all.
\"Bypassing the light detector\" means that I connect the battery positive to the center of the transformer directly, without going through the first transistor so that the transformer is always powered by the battery as far as it is charged. This works with or without the solar panel, with or without light on it.

I am interested in making the light detector work, to switch on the light only when meaningful and to maintain the battery charged.

Eventually, I would also try to replace the battery with a capacitor but I am not 100% sure this is a good idea. And I would like to know the frequency of oscillation, I don\'t know if there is a practical way to calculate it, I do not an oscilloscope.

Thanks link too!

Switching the main current to the Joule Theif is probably the wrong
approach, switch the current to the base instead, that is only switch
the current that flows through the transformer branch that goes to the
base. this is a much smaller current, and so it takes less energy to
run the switch. (you can use a smaller base current to the switch)

A second problem is that the joule thief may not start automatically
when power is gradually applied. Some sort of positive feedback to
ensure that the power snaps on should help there.

How do you plan to switch only the base of the oscillator transistor?

https://www.jameco.com/Jameco/workshop/JamecoFavorites/solarled.html

the transformer has two windings, connect the other one to the supply.

The windiings have the turn on bias a well as the inductive feedback
and turn-off riding on them. The center-tap is integral to the
operation..

it\'s just a node.

There should be a way to do it: pass the AC feedback while isolating
the DC bias,

current into the base is close enough to monodirectional that it
doesn\'t matter.

but it is a little more complicated than separating the
center tap and it would take a few more components.

a capacitor across the added transistor could maybe help with charge
scavenging a little but that 1K resistor is going to slow that down
anyway.

So you have... nothing. Post a schematic.

 

[Jasen Betts]

On 2020-05-29, default <default@defaulter.net> wrote:

On Fri, 29 May 2020 06:02:32 -0000 (UTC), Jasen Betts
jasen@xnet.co.nz> wrote:

So you have... nothing. Post a schematic.

No, asshole, I have built it and it works. I am not wasting any
further time responding to your clueless taunts with useful
information.


--
Jasen.

 

[Jasen Betts]

On 2020-05-29, default <default@defaulter.net> wrote:

On Fri, 29 May 2020 06:02:32 -0000 (UTC), Jasen Betts
jasen@xnet.co.nz> wrote:

So you have... nothing. Post a schematic.

No, asshole, I have built it and it works. I am not wasting any
further time responding to your clueless taunts with useful
information.


--
Jasen.

 

[Jasen Betts]

On 2020-05-29, default <default@defaulter.net> wrote:

On Fri, 29 May 2020 06:02:32 -0000 (UTC), Jasen Betts
jasen@xnet.co.nz> wrote:

So you have... nothing. Post a schematic.

No, asshole, I have built it and it works. I am not wasting any
further time responding to your clueless taunts with useful
information.


--
Jasen.

 

[server]

Ok guys, I tried!
If I directly connect the PNP base to battery negative the LED lights up as bright as possible but it never turns off, even if I put everything in the sun.
If I add a 5k resistor between PNP base and battery negative it works as expected, so it automatically turn on and off according to the amount of light on the solar panel, but the led brightness is not much even when I cover the panel or if I disconnect it.
Ideas?

Thanks a lot!

 

[server]

Ok guys, I tried!
If I directly connect the PNP base to battery negative the LED lights up as bright as possible but it never turns off, even if I put everything in the sun.
If I add a 5k resistor between PNP base and battery negative it works as expected, so it automatically turn on and off according to the amount of light on the solar panel, but the led brightness is not much even when I cover the panel or if I disconnect it.
Ideas?

Thanks a lot!

 

[server]

Ok guys, I tried!
If I directly connect the PNP base to battery negative the LED lights up as bright as possible but it never turns off, even if I put everything in the sun.
If I add a 5k resistor between PNP base and battery negative it works as expected, so it automatically turn on and off according to the amount of light on the solar panel, but the led brightness is not much even when I cover the panel or if I disconnect it.
Ideas?

Thanks a lot!

 

[Jasen Betts]

On 2020-06-07, alberto.m.scattolo@gmail.com <alberto.m.scattolo@gmail.com> wrote:

Ok guys, I tried!
If I directly connect the PNP base to battery negative the LED lights up as bright as possible but it never turns off, even if I put everything in the sun.
If I add a 5k resistor between PNP base and battery negative it works as expected, so it automatically turn on and off according to the amount of light on the solar panel, but the led brightness is not much even when I cover the panel or if I disconnect it.
Ideas?

Thanks a lot!

Changing the transformer so the top end of the winding that goes from
the PNP collector to the NPN collector instead is connected from
pattery positive to NPN collector will improve brightness.

Leave the winding that goes from PNP collector to the resistor that
goes to the NPN base connected to the PNP collector and resistor

--
Jasen.

 

[default]

On Sat, 30 May 2020 05:32:30 -0000 (UTC), Jasen Betts
<jasen@xnet.co.nz> wrote:

On 2020-05-29, default <default@defaulter.net> wrote:
On Fri, 29 May 2020 06:02:32 -0000 (UTC), Jasen Betts
jasen@xnet.co.nz> wrote:

So you have... nothing. Post a schematic.

No, asshole, I have built it and it works. I am not wasting any
further time responding to your clueless taunts with useful
information.

ROFLMAO

sure you built it

 

[RheillyPhoull]

On 30/05/2020 5:11 pm, default wrote:

On Sat, 30 May 2020 05:32:30 -0000 (UTC), Jasen Betts
jasen@xnet.co.nz> wrote:

On 2020-05-29, default <default@defaulter.net> wrote:
On Fri, 29 May 2020 06:02:32 -0000 (UTC), Jasen Betts
jasen@xnet.co.nz> wrote:

So you have... nothing. Post a schematic.

No, asshole, I have built it and it works. I am not wasting any
further time responding to your clueless taunts with useful
information.

ROFLMAO

sure you built it

Nice to see you guys getting along

 

[RheillyPhoull]

On 30/05/2020 5:11 pm, default wrote:

On Sat, 30 May 2020 05:32:30 -0000 (UTC), Jasen Betts
jasen@xnet.co.nz> wrote:

On 2020-05-29, default <default@defaulter.net> wrote:
On Fri, 29 May 2020 06:02:32 -0000 (UTC), Jasen Betts
jasen@xnet.co.nz> wrote:

So you have... nothing. Post a schematic.

No, asshole, I have built it and it works. I am not wasting any
further time responding to your clueless taunts with useful
information.

ROFLMAO

sure you built it

Nice to see you guys getting along

 

[RheillyPhoull]

On 30/05/2020 5:11 pm, default wrote:

On Sat, 30 May 2020 05:32:30 -0000 (UTC), Jasen Betts
jasen@xnet.co.nz> wrote:

On 2020-05-29, default <default@defaulter.net> wrote:
On Fri, 29 May 2020 06:02:32 -0000 (UTC), Jasen Betts
jasen@xnet.co.nz> wrote:

So you have... nothing. Post a schematic.

No, asshole, I have built it and it works. I am not wasting any
further time responding to your clueless taunts with useful
information.

ROFLMAO

sure you built it

Nice to see you guys getting along

 

[server]

Oh guys, come on.
Unfortunately I still cannot try your suggestions as I am not at home, but please, let\'s try to be pragmatic.
If any of you have ideas, schematics or whatever, post it. I have limited components at home and some are just scavengered but I would give a try to any good idea that would allow me to keep 4 bright led on all night long.

BTW, is replacing the battery with a capacitor an idea worth trying/meaningful?

Thank you all

 

[server]

Oh guys, come on.
Unfortunately I still cannot try your suggestions as I am not at home, but please, let\'s try to be pragmatic.
If any of you have ideas, schematics or whatever, post it. I have limited components at home and some are just scavengered but I would give a try to any good idea that would allow me to keep 4 bright led on all night long.

BTW, is replacing the battery with a capacitor an idea worth trying/meaningful?

Thank you all

 

[server]

Oh guys, come on.
Unfortunately I still cannot try your suggestions as I am not at home, but please, let\'s try to be pragmatic.
If any of you have ideas, schematics or whatever, post it. I have limited components at home and some are just scavengered but I would give a try to any good idea that would allow me to keep 4 bright led on all night long.

BTW, is replacing the battery with a capacitor an idea worth trying/meaningful?

Thank you all

 

[default]

On Sun, 7 Jun 2020 07:30:42 -0700 (PDT), alberto.m.scattolo@gmail.com
wrote:

Ok guys, I tried!
If I directly connect the PNP base to battery negative the LED lights up as bright as possible but it never turns off, even if I put everything in the sun.
If I add a 5k resistor between PNP base and battery negative it works as expected, so it automatically turn on and off according to the amount of light on the solar panel, but the led brightness is not much even when I cover the panel or if I disconnect it.
Ideas?

Thanks a lot!

Have you tried looking for a happy medium resistance? You want to
turn on the PNP and drive it into saturation (ideally) and have it
turn off when the panel is making electricity.

It is never good practice to connect the base of a bipolar transistor
to forward bias it without some current limiting resistor. If your
transistor survived, it is only because the battery wasn\'t powerful
enough to fry it.

The ideal size resistor depends on the current gain of the transistor.
Gain is specified at a particular collector current in the datasheet
and there may be a graph too.

Small signal transistors usually have gains of ~100. So with 1
milliamp flowing in the base you should get 100 in the collector
circuit. (more or less... gains can be specified as some minimum and
the maximum, for a production run of parts, can be several times
higher)

 

[default]

On Sun, 7 Jun 2020 07:30:42 -0700 (PDT), alberto.m.scattolo@gmail.com
wrote:

Ok guys, I tried!
If I directly connect the PNP base to battery negative the LED lights up as bright as possible but it never turns off, even if I put everything in the sun.
If I add a 5k resistor between PNP base and battery negative it works as expected, so it automatically turn on and off according to the amount of light on the solar panel, but the led brightness is not much even when I cover the panel or if I disconnect it.
Ideas?

Thanks a lot!

Have you tried looking for a happy medium resistance? You want to
turn on the PNP and drive it into saturation (ideally) and have it
turn off when the panel is making electricity.

It is never good practice to connect the base of a bipolar transistor
to forward bias it without some current limiting resistor. If your
transistor survived, it is only because the battery wasn\'t powerful
enough to fry it.

The ideal size resistor depends on the current gain of the transistor.
Gain is specified at a particular collector current in the datasheet
and there may be a graph too.

Small signal transistors usually have gains of ~100. So with 1
milliamp flowing in the base you should get 100 in the collector
circuit. (more or less... gains can be specified as some minimum and
the maximum, for a production run of parts, can be several times
higher)