Comments on: Building a FRED Photopopper

By: Gabriella Levine » Blog Archive » BeamBot

Gabriella Levine » Blog Archive » BeamBot — Mon, 21 Mar 2011 21:17:08 +0000

[...] Here are some helpful links for the BEAM photopopper I hope to build: Solarbotics tutorials Beam circuits Fred Photopopper another Fred Photopopper tutorial [...]

By: gaihre arjun

gaihre arjun — Fri, 14 Jan 2011 13:29:46 +0000

the images given r not clearly visible…and don’t we get the image that is hand drawn also….

By: p.guru murthy

p.guru murthy — Wed, 17 Feb 2010 12:19:08 +0000

i could manage to get 6×5 solar panel-4 volts, 150 mA, smaller size and lesser amps solar panels are not available.due to more current the circuit operation is stalling in direct sun light.what is the correct solution , sir ?

By: William Cox

William Cox — Fri, 30 Oct 2009 14:12:25 +0000

Dil,
I can’t say for certain whether the switch will work. I’m not super familiar with the intricacies of Ben’s circuit. Looking at the datasheets, it appears that the BC550 is a lower power transistor than the BC337. As the photopopper is a low power circuit to begin with, I think you should be fine. Give it a shot and let us know how it goes!

By: dil

dil — Fri, 30 Oct 2009 11:55:23 +0000

hello,
Can I use bc550 and bc557 instead of bc337 and bc327, respectively? Thanks!

By: baba

baba — Tue, 01 Sep 2009 05:24:42 +0000

hii william ,

can u put a pic of ur working model here ………

it would be a great help ……

i wana work on dis project ……..

so plz just put a pic or give me a link where i can see its working pic ……..

By: tom

tom — Thu, 25 Jun 2009 18:00:51 +0000

wow thanks for the super fast reply much appreciated

By: William Cox

William Cox — Thu, 25 Jun 2009 17:55:28 +0000

Tom, generally the capacitors have a white stripe down the side that indicates the negative (“-”) side of things.

By: tom

tom — Thu, 25 Jun 2009 17:50:30 +0000

just a little question iv got some 3300 uF capacitors out a old circuit how do i know what side is + ??

By: srbin

srbin — Fri, 08 May 2009 14:55:20 +0000

I live in Serbia we dont have that kind of solar cells witch one can i buy (not over the internet)?

By: Adam

Adam — Thu, 02 Apr 2009 00:00:24 +0000

Denny,
I’ve tried many solar panels, high voltages (6+) and currents (80mA) and low(1.2V, 1.5mA).
The key is getting the voltage right. If you use a high voltage solar panel for a circuit designed for lower voltage you will get erratic behavior. Sometimes firing, firing once and then not again until removed from the sun. Solution to high voltage is using different components, ie. higher V 1381 or add some diodes in series near the ground.
As far as amperage, higher = quicker charging. As long as you’re in the range of say 1uA to 100mA it should just be about duration between firing. I’ve not built a solar engine which didn’t fire – pause – fire. If your panel is that powerful it must be huge or the components you are using need to be adjusted.
Best solar panels for Miller and Fred are 3 – 6 V and 15+ mA.

By: denny

denny — Sun, 25 Jan 2009 00:43:25 +0000

very interesting mod.
I have a question.”NOBODY” has addressed solar cell types or voltage ranges.
Everybody seems to use the panasonic,but what about other ones.What range of
voltage should I stay in,more important,what miliamps.Some claim you need only a few microamps.(never worked for me)others say a few mili amps(if I go above
10or 12 in full sun light it will run constantly without cycling)is that a mistake?
I was wondering if you could write about solar requirements.
Many thanks

By: William Cox

William Cox — Tue, 20 Jan 2009 14:46:46 +0000

Nimit,
I think that solar cell should work fine. All the circuit components look like they should work with a 6v solar cell. Good luck building! Let me know how it turns out.

By: nimit

nimit — Tue, 20 Jan 2009 11:05:43 +0000

Sir

Thanks for replying. Local Vendor has a solar panel with config 6Volts , 84mA.
Can this be used. Will it affect other components in the circuit

By: William Cox

William Cox — Mon, 19 Jan 2009 16:02:18 +0000

Nimit,
Check out the solar cells that Solarbotics sells (http://www.solarbotics.com/solar_cells/). Any of the large ones should work. The bigger the cell, though, the more Fred will move (higher current).

By: nimit

nimit — Sat, 17 Jan 2009 14:33:18 +0000

Sir

I am from india. Solar Cell Part # BP-243318 is not available here. Can you please provide the specifications of the solar cell so that i can find similar product here

regards
nimit
nsit, delhi

By: viaani

viaani — Thu, 30 Oct 2008 01:29:12 +0000

hola esta mui interesante tu trabajo

By: joel

joel — Tue, 10 Jun 2008 01:16:46 +0000

i just completed my fred v 1.5 and it is amasing thanks for sharing the specs with everyone and good job !!!!!!!!!!!!!!