1.5v - 1w >>> Solar?

[CCinPA`cr]

Feel free to throw me out of here because of such a simple question... But here I go:

I need to power a 1.5v 1w device (consistently)
- Just during daylight hours
- Able to tolerate variations in sunlight

What else would you need to know that would help?

Help?

 

[Dan]

Nobody is throwing you out for simple questions

I'm sure somebody will be along to help soon enough.

 

[marconi]

Because you mention the sun I assume you want to use a photovoltaic cell. One would need to know more about the user's requirement. Here are some questions on the UR;

1. it may sound daft - but what exactly do you mean by 'during daylight hours'? Do you mean from sunrise to sunset? Or do you mean from a specific hour in the morning to a specific hour in the evening for every day of the year?

2. Is it acceptable that when the sun is obscured by clouds the device loses power? If it is not acceptable then how long do you want power to be provided by a battery or capacitor?

3. Will the solar pv cell ever be obscured from the sun by physical objects?

4. What is the nature of the load ? Constant, random, periodic, use/user determined? Peak current? Average current?

5. What is the consequence of no power being available to the load? Does this matter much?

6. What is the operating environment? Temperature range, water/rain/ice/dew/snow, vibration, dust/debris/detritus, pressure, ...

7. Do you want the solar cell to be able to power the device and charge a flat battery at the same time?

8. What is the required lifetime without maintenance?

9. Where in the world do you want the device to work satisfactorily?

 

[CCinPA`cr]

Because you mention the sun I assume you want to use a photovoltaic cell. One would need to know more about the user's requirement. Here are some questions on the UR;

1. it may sound daft - but what exactly do you mean by 'during daylight hours'? Do you mean from sunrise to sunset? Or do you mean from a specific hour in the morning to a specific hour in the evening for every day of the year?
>>>Sunrise to sunset - Using Memorial-day to Labor-day

2. Is it acceptable that when the sun is obscured by clouds the device loses power? If it is not acceptable then how long do you want power to be provided by a battery or capacitor?
>>>Device should run continuously... Regardless of cloud-cover

3. Will the solar pv cell ever be obscured from the sun by physical objects?
>>>No

4. What is the nature of the load ? Constant, random, periodic, use/user determined? Peak current? Average current?
>>>The load is constant - As far as "average current" is the device is 1.5v @ 1w

5. What is the consequence of no power being available to the load? Does this matter much?
>>>Matters much

6. What is the operating environment? Temperature range, water/rain/ice/dew/snow, vibration, dust/debris/detritus, pressure, ...
>>> Clean environment - Weather associated with Central-PA USA

7. Do you want the solar cell to be able to power the device and charge a flat battery at the same time?
>>> Any solution that would allow the device to run continuously

8. What is the required lifetime without maintenance?
>>> Memorial-day to Labor-day for as many years as possible

9. Where in the world do you want the device to work satisfactorily?
>>> Carmen Sandiego lives in Central-PA United States of America <grin>

 

[Megawatt]

Because you mention the sun I assume you want to use a photovoltaic cell. One would need to know more about the user's requirement. Here are some questions on the UR;

1. it may sound daft - but what exactly do you mean by 'during daylight hours'? Do you mean from sunrise to sunset? Or do you mean from a specific hour in the morning to a specific hour in the evening for every day of the year?

>>Sunrise to sunset - Using Memorial-day to Labor-day

2. Is it acceptable that when the sun is obscured by clouds the device loses power? If it is not acceptable then how long do you want power to be provided by a battery or capacitor?

>>Device should run continuously... Regardless of cloud-cover

3. Will the solar pv cell ever be obscured from the sun by physical objects?

>>No

4. What is the nature of the load ? Constant, random, periodic, use/user determined? Peak current? Average current?

>>The load is constant - As far as "average current" is the device is 1.5v @ 1w

5. What is the consequence of no power being available to the load? Does this matter much?

>>Matters much

6. What is the operating environment? Temperature range, water/rain/ice/dew/snow, vibration, dust/debris/detritus, pressure, ...

>> Clean environment - Weather associated with Central-PA USA

7. Do you want the solar cell to be able to power the device and charge a flat battery at the same time?

>> Any solution that would allow the device to run continuously

8. What is the required lifetime without maintenance?

>> Memorial-day to Labor-day for as many years as possible

9. Where in the world do you want the device to work satisfactorily?

>> Carmen Sandiego lives in Central-PA United States of America <grin>

CC as you can see there are a lot of questions that need to be answered and what’s up with the flag thing ?

 

[CCinPA`cr]

There may be questions I did not answer. I've got a layout I want to try... But need help how to connect the wires please? So what are the new questions and any old unanswered?

 

[buzzlightyear]

That advitar must be the coolest yet.

 

[CCinPA`cr]

Today... I tested without the buck-converter. Although I had 12+-volts into the photocell... No output from the photocell with/without sunlight.

 

[marconi]

Sometimes there is a delay before the photocell switches on or off in response to ambient light in order not to react say to passing clouds reducing the light level during the day. Perhaps try again but wait a little longer.

Could you give details of the photocell so I can look up its specification for you?

 

[CCinPA`cr]

Here's all I know so far...

 

[marconi]

I suppose the first possibility is the photo-switch(PS) is defective which I will cover shortly.

First the wiring:

a. For the photo-voltaic (PV) panel, batteries, DC-DC converter and load, red is positive(+) and black is (-).

b. For the PS, the input should be wired black as positive(+), and white as (-) and the red is a switched positive(+) output.

c. The DC-DC converter is connected between the red and the white of the PS.

d. The butterfly is connected such that its positive goes to the yellow of the DC-DC converter and its black to the black of the converter.

Now back to the PS. There is a single screw holding the lid in place. Please unscrew it and then carefully withdraw the circuit board. Before you do anything else could you take some photos of the top and bottom of the board?

You should see a component called a photoresistor which is similar to this:

To check the circuit is working, could you connect up your circuit and place a multi-meter if you have one set to read dc voltage and 12-20V across the red and black of the PS. With daylight shining on the photo-resistor the output should be zero Volts.

Using a short length of single core wire, strip the insulation by 5mm of each end, and then carefully use this wire to short out the photo-resistor by attaching it across the two wire leads to the photo-resistor. Wait and listen carefully for the click of the relay. Do this a few times. If you hear no click of the relay then it indicates the circuit is defective in some way. If you do hear a click check then for a 12V reading on you multi-meter; if there is 12V then the PS is working. If the output remains at zero Volts even though you have heard the relay click then this indicates a fault with the board.

Be very careful not to accidentally touch any other contacts when you short out the photo-resistor because it could cause some damage.

Let me know what you find out.


Marconi

 

[marconi]

In case you had not thought of it, put a fuse in series with each red wire to the batteries to protect against short circuit. Auto-electric suppliers will have in-line fuses for sale. I suggest without knowing more a 5A fuse. Place them close to the terminals.

 

[CCinPA`cr]

I was offline for a bit. I'm going to order additional sensors. Then I'll be back!
[automerge]1571096577[/automerge]

I suppose the first possibility is the photo-switch(PS) is defective which I will cover shortly.

First the wiring:

a. For the photo-voltaic (PV) panel, batteries, DC-DC converter and load, red is positive(+) and black is (-).

b. For the PS, the input should be wired black as positive(+), and white as (-) and the red is a switched positive(+) output.

c. The DC-DC converter is connected between the red and the white of the PS.

d. The butterfly is connected such that its positive goes to the yellow of the DC-DC converter and its black to the black of the converter.

Now back to the PS. There is a single screw holding the lid in place. Please unscrew it and then carefully withdraw the circuit board. Before you do anything else could you take some photos of the top and bottom of the board?

You should see a component called a photoresistor which is similar to this:

View attachment 52841


To check the circuit is working, could you connect up your circuit and place a multi-meter if you have one set to read dc voltage and 12-20V across the red and black of the PS. With daylight shining on the photo-resistor the output should be zero Volts.

Using a short length of single core wire, strip the insulation by 5mm of each end, and then carefully use this wire to short out the photo-resistor by attaching it across the two wire leads to the photo-resistor. Wait and listen carefully for the click of the relay. Do this a few times. If you hear no click of the relay then it indicates the circuit is defective in some way. If you do hear a click check then for a 12V reading on you multi-meter; if there is 12V then the PS is working. If the output remains at zero Volts even though you have heard the relay click then this indicates a fault with the board.

Be very careful not to accidentally touch any other contacts when you short out the photo-resistor because it could cause some damage.

Let me know what you find out.


Marconi

I'm not ignoring your suggestions. Just wasn't sure with my lack of electronics I could have been successful.