Repair water damaged Solar Garden Lamp
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From: GregS on 22 Feb 2010 14:03 In article <1b01c098-633d-4125-9086-3c1f5f38b877(a)y17g2000yqd.googlegroups.com>, mpm <mpmillard(a)aol.com> wrote: >On Feb 22, 11:40=A0am, Dave_s <grou...(a)dslextreme.com> wrote: >> Athttp://s1001.photobucket.com/albums/af140/Dave_ss/Garden%20Solar%20La..= >.. >> are pictures of my water damaged Solar Garden Lamps. >> >> Pictures show the damaged Solar Garden Lamps I need to repair. The OEM >> long ago discontinued this product making impossible to buy replacement >> gaskets and parts for the electronics. >> >> I am trying to repair these units. >> >> I need to buy replacement resistors and diodes. >> >> The resistors are smaller than normal 1/4W parts and the pad =A0lead hole= >s >> =A0 are too small for 1/4W parts. Same problem with the diode. It looks >> like a mini smaller 1N4001 =A0package with much smaller diameter leads >> holes in pads. >> >> The transistor is marked STS but I cannot find any info for this part at >> STS web site. Is this a FET or bipolar. Need datasheet to find ratings. >> Thank you for any help. Dave_s > >They make 1/8th-watt, 1/10-watt resistors, and even 1/16th and 1/20th- >watt resistors. >All of these are physically smaller than standard 1/4-watt >resistors. Digikey carries them. > >Not sure what the diode function is (no schematic), but it's probably >just being used to isolate the NiCad from the solar cell. (?) >If so, I'll bet any diode that fits will (should) work. Maybe a >1N914. They're tiny. > >STS is probably the manufacturer. ?? >Again, probably just used as a simple switch. So maybe a 2N3904 or >2N3906 would do? >Keep in mind these are all total guesses. > >Personally, I would put a voltmeter on the solar cell first and make >sure there's some output in direct sunlight. >Would be a bummer to find the device basically works, but it's not >charging itself. >And as others have stated, I wouldn't "trust" a NiCad in the garden >for too many seasons.... > >Good luck. I have had good luck with NiMH cells in the garden, but these types of lamps need constant attention. Can't tell from the picture how much damage, but water cleans most green stuff away, then protect. greg
From: Paul E. Schoen on 23 Feb 2010 03:00 "Dave_s" <group78(a)dslextreme.com> wrote in message news:Gsygn.53313$Ee1.31891(a)newsfe12.iad... > At > http://s1001.photobucket.com/albums/af140/Dave_ss/Garden%20Solar%20Lamps%20Repair/?action=view¤t=Water-inside-solar-garden-lamp-CORR.jpg > are pictures of my water damaged Solar Garden Lamps. > > Pictures show the damaged Solar Garden Lamps I need to repair. The OEM > long ago discontinued this product making impossible to buy replacement > gaskets and parts for the electronics. > > I am trying to repair these units. > > I need to buy replacement resistors and diodes. > > The resistors are smaller than normal 1/4W parts and the pad lead holes > are too small for 1/4W parts. Same problem with the diode. It looks > like a mini smaller 1N4001 package with much smaller diameter leads > holes in pads. > > The transistor is marked STS but I cannot find any info for this part at > STS web site. Is this a FET or bipolar. Need datasheet to find ratings. > Thank you for any help. Dave_s I think these lamps usually use a "joule thief" type circuit which can generate the required 3 VDC or so for the white LED from mostly depleted NiCd cells down to 2 VDC or less. But that would indicate a little inductor/transformer, which I don't see in the photos. I made the following "joule thief" circuit which actually regulates the LED current over a range of battery voltages, and I have attached the LTSpice schematic. I actually built the circuit and it drives two large white LEDs in series with as low as 2 VDC, and it's fairly efficient. What is also lacking is the charging circuit from the photovoltaic cells to the battery. It might be just a Schottky diode. Some components in the attached circuit may not be required, and values are not critical. If you do a search you may find very simple circuits and even one or two that use a bunch of turns of wire on a nail for the tapped inductor. Maybe you can roll your own circuit as a deadbug and then encapsulate it in electrical grade silicone. Paul -------------------------------------------------------------- Version 4 SHEET 1 880 680 WIRE 80 0 -112 0 WIRE 208 0 80 0 WIRE 80 16 80 0 WIRE 208 16 208 0 WIRE 208 112 208 96 WIRE 368 112 208 112 WIRE -112 128 -112 0 WIRE 80 128 80 96 WIRE 208 176 208 112 WIRE 80 224 80 208 WIRE 80 224 0 224 WIRE 96 224 80 224 WIRE 144 224 96 224 WIRE 0 240 0 224 WIRE 96 256 96 224 WIRE 192 304 160 304 WIRE 288 304 272 304 WIRE 368 304 352 304 WIRE 496 304 368 304 WIRE 272 320 272 304 WIRE 496 320 496 304 WIRE -112 384 -112 208 WIRE 0 384 0 304 WIRE 0 384 -112 384 WIRE 96 384 96 352 WIRE 96 384 0 384 WIRE 208 384 208 272 WIRE 208 384 96 384 WIRE 272 384 208 384 WIRE 368 384 272 384 WIRE 496 384 368 384 WIRE 368 432 368 384 FLAG 368 432 0 SYMBOL npn 144 176 R0 WINDOW 0 33 47 Left 0 SYMATTR InstName Q1 SYMATTR Value 2N2219A SYMBOL ind2 96 112 R180 WINDOW 0 36 80 Left 0 WINDOW 3 36 40 Left 0 SYMATTR InstName L1 SYMATTR Value 800� SYMATTR Type ind SYMBOL ind2 192 0 R0 SYMATTR InstName L2 SYMATTR Value 100� SYMATTR Type ind SYMBOL LED 352 240 R0 WINDOW 3 22 69 Left 0 SYMATTR InstName D1 SYMATTR Value AOT-2015 SYMBOL res 64 112 R0 SYMATTR InstName R1 SYMATTR Value 1k SYMBOL voltage -112 112 R0 WINDOW 123 0 0 Left 0 WINDOW 39 0 0 Left 0 SYMATTR InstName V1 SYMATTR Value 3 SYMBOL LED 352 112 R0 SYMATTR InstName D2 SYMATTR Value AOT-2015 SYMBOL schottky 16 304 R180 WINDOW 0 24 72 Left 0 WINDOW 3 24 0 Left 0 SYMATTR InstName D3 SYMATTR Value 1N5818 SYMATTR Description Diode SYMATTR Type diode SYMBOL LED 352 176 R0 SYMATTR InstName D4 SYMATTR Value AOT-2015 SYMBOL res 352 288 R0 SYMATTR InstName R2 SYMATTR Value 30 SYMBOL npn 160 256 M0 WINDOW 0 33 47 Left 0 SYMATTR InstName Q2 SYMATTR Value 2N2219A SYMBOL schottky 352 288 R90 WINDOW 0 0 32 VBottom 0 WINDOW 3 32 32 VTop 0 SYMATTR InstName D5 SYMATTR Value 1N5818 SYMATTR Description Diode SYMATTR Type diode SYMBOL cap 256 320 R0 SYMATTR InstName C1 SYMATTR Value 100n SYMBOL res 288 288 R90 WINDOW 0 0 56 VBottom 0 WINDOW 3 34 46 VTop 0 SYMATTR InstName R3 SYMATTR Value 1k SYMBOL cap 480 320 R0 SYMATTR InstName C2 SYMATTR Value 10� TEXT 280 72 Left 0 !K1 L1 L2 1 TEXT -66 360 Left 0 !.tran 10m startup
From: Martin Brown on 23 Feb 2010 03:36 Paul E. Schoen wrote: > > I think these lamps usually use a "joule thief" type circuit which can > generate the required 3 VDC or so for the white LED from mostly depleted > NiCd cells down to 2 VDC or less. But that would indicate a little > inductor/transformer, which I don't see in the photos. I made the following > "joule thief" circuit which actually regulates the LED current over a range > of battery voltages, and I have attached the LTSpice schematic. I actually > built the circuit and it drives two large white LEDs in series with as low > as 2 VDC, and it's fairly efficient. That is certainly the most common over here. You should not assume the batteries are wired in series though - some of mine are in parallel. I was quite surprised when it started working with only one cell replaced. Adding the second cell in parallel made it brighter. I guess this allows them to save on components with a corresponding loss of efficiency. In the UK the very long summer twilight makes it worth adjusting the switch on point to much darker than the default manufacturers setting which assumes a latitude of 30 degrees or so. In winter they die a horrible death outside here alternately freezing and being totally discharged for days on end. The batteries do not like this treatment at all. The ones installed on roadside safety signs like "beware bend" always fail in the worst icy foggy weather. Regards, Martin Brown
From: Robert Baer on 23 Feb 2010 05:02 Paul E. Schoen wrote: > "Dave_s" <group78(a)dslextreme.com> wrote in message > news:Gsygn.53313$Ee1.31891(a)newsfe12.iad... >> At >> http://s1001.photobucket.com/albums/af140/Dave_ss/Garden%20Solar%20Lamps%20Repair/?action=view¤t=Water-inside-solar-garden-lamp-CORR.jpg >> are pictures of my water damaged Solar Garden Lamps. >> >> Pictures show the damaged Solar Garden Lamps I need to repair. The OEM >> long ago discontinued this product making impossible to buy replacement >> gaskets and parts for the electronics. >> >> I am trying to repair these units. >> >> I need to buy replacement resistors and diodes. >> >> The resistors are smaller than normal 1/4W parts and the pad lead holes >> are too small for 1/4W parts. Same problem with the diode. It looks >> like a mini smaller 1N4001 package with much smaller diameter leads >> holes in pads. >> >> The transistor is marked STS but I cannot find any info for this part at >> STS web site. Is this a FET or bipolar. Need datasheet to find ratings. >> Thank you for any help. Dave_s > > I think these lamps usually use a "joule thief" type circuit which can > generate the required 3 VDC or so for the white LED from mostly depleted > NiCd cells down to 2 VDC or less. But that would indicate a little > inductor/transformer, which I don't see in the photos. I made the following > "joule thief" circuit which actually regulates the LED current over a range > of battery voltages, and I have attached the LTSpice schematic. I actually > built the circuit and it drives two large white LEDs in series with as low > as 2 VDC, and it's fairly efficient. > > What is also lacking is the charging circuit from the photovoltaic cells to > the battery. It might be just a Schottky diode. > > Some components in the attached circuit may not be required, and values are > not critical. If you do a search you may find very simple circuits and even > one or two that use a bunch of turns of wire on a nail for the tapped > inductor. Maybe you can roll your own circuit as a deadbug and then > encapsulate it in electrical grade silicone. > > Paul > > -------------------------------------------------------------- > Version 4 > SHEET 1 880 680 > WIRE 80 0 -112 0 > WIRE 208 0 80 0 > WIRE 80 16 80 0 > WIRE 208 16 208 0 > WIRE 208 112 208 96 > WIRE 368 112 208 112 > WIRE -112 128 -112 0 > WIRE 80 128 80 96 > WIRE 208 176 208 112 > WIRE 80 224 80 208 > WIRE 80 224 0 224 > WIRE 96 224 80 224 > WIRE 144 224 96 224 > WIRE 0 240 0 224 > WIRE 96 256 96 224 > WIRE 192 304 160 304 > WIRE 288 304 272 304 > WIRE 368 304 352 304 > WIRE 496 304 368 304 > WIRE 272 320 272 304 > WIRE 496 320 496 304 > WIRE -112 384 -112 208 > WIRE 0 384 0 304 > WIRE 0 384 -112 384 > WIRE 96 384 96 352 > WIRE 96 384 0 384 > WIRE 208 384 208 272 > WIRE 208 384 96 384 > WIRE 272 384 208 384 > WIRE 368 384 272 384 > WIRE 496 384 368 384 > WIRE 368 432 368 384 > FLAG 368 432 0 > SYMBOL npn 144 176 R0 > WINDOW 0 33 47 Left 0 > SYMATTR InstName Q1 > SYMATTR Value 2N2219A > SYMBOL ind2 96 112 R180 > WINDOW 0 36 80 Left 0 > WINDOW 3 36 40 Left 0 > SYMATTR InstName L1 > SYMATTR Value 800� > SYMATTR Type ind > SYMBOL ind2 192 0 R0 > SYMATTR InstName L2 > SYMATTR Value 100� > SYMATTR Type ind > SYMBOL LED 352 240 R0 > WINDOW 3 22 69 Left 0 > SYMATTR InstName D1 > SYMATTR Value AOT-2015 > SYMBOL res 64 112 R0 > SYMATTR InstName R1 > SYMATTR Value 1k > SYMBOL voltage -112 112 R0 > WINDOW 123 0 0 Left 0 > WINDOW 39 0 0 Left 0 > SYMATTR InstName V1 > SYMATTR Value 3 > SYMBOL LED 352 112 R0 > SYMATTR InstName D2 > SYMATTR Value AOT-2015 > SYMBOL schottky 16 304 R180 > WINDOW 0 24 72 Left 0 > WINDOW 3 24 0 Left 0 > SYMATTR InstName D3 > SYMATTR Value 1N5818 > SYMATTR Description Diode > SYMATTR Type diode > SYMBOL LED 352 176 R0 > SYMATTR InstName D4 > SYMATTR Value AOT-2015 > SYMBOL res 352 288 R0 > SYMATTR InstName R2 > SYMATTR Value 30 > SYMBOL npn 160 256 M0 > WINDOW 0 33 47 Left 0 > SYMATTR InstName Q2 > SYMATTR Value 2N2219A > SYMBOL schottky 352 288 R90 > WINDOW 0 0 32 VBottom 0 > WINDOW 3 32 32 VTop 0 > SYMATTR InstName D5 > SYMATTR Value 1N5818 > SYMATTR Description Diode > SYMATTR Type diode > SYMBOL cap 256 320 R0 > SYMATTR InstName C1 > SYMATTR Value 100n > SYMBOL res 288 288 R90 > WINDOW 0 0 56 VBottom 0 > WINDOW 3 34 46 VTop 0 > SYMATTR InstName R3 > SYMATTR Value 1k > SYMBOL cap 480 320 R0 > SYMATTR InstName C2 > SYMATTR Value 10� > TEXT 280 72 Left 0 !K1 L1 L2 1 > TEXT -66 360 Left 0 !.tran 10m startup > > I have seen and messed with a number of "solar garden lights" and they all use a 1n4005 or equivalent to isolate the silicon solar cell from the battery (so battery will not discharge into solar cell). One can use a schottky for slightly better efficiency. Most 2-transistor schemes use an NPN and a PNP to make an oscillator to drive a small inductor that pulses the LED, but some use two NPNs. See if they have exactly the same markings (both NPN),or are different (NPN / PNP). Any generic "small signal" silicon transistors will work. If after cleanup it still does not work,i would suspect that the PCB has adsorbed a lot of alkaline type crud from the batteries..so replacing is best.
From: Sylvia Else on 23 Feb 2010 17:53
On 23/02/2010 7:36 PM, Martin Brown wrote: > In winter they die a horrible death outside here alternately freezing > and being totally discharged for days on end. The batteries do not like > this treatment at all. The ones installed on roadside safety signs like > "beware bend" always fail in the worst icy foggy weather. Sounds like they'd be causing more accidents than they prevent if people end up relying on them and they don't work when most needed. Sylvia. |