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hey guys i m particpatin in a solar boat race competeion nn desprately need ur help. heres d link for competion rules Answered

heres d link for competion rules :   http://redirectingat.com/?id=487X782&url=http%3A%2F%2Fwww.techfest.org%2Fcompetitions%2Ftorque%2Fsolarsplash%2F

i dnt hv n e practical experience with solar engines. i bought my self a 4700 micro farad cap and trying to build with it. can any one tell me how can i increase the tripping voltage for ic 1381 .. i have 1381 c   and its trpping voltage is very low 2 volts .. how can super capacitor help me ?


> Take this to PM Mihir, we're running out of space to talk !!!!
.  Or start a new thread.

Try and write with all the extra letters - I can't read this question properly. You don't get charged extra for vowels.

hey guys i am particpating in a solar boat race competeion and desprately need your help.

heres thenk for competion rules :   http://redirectingat.com/?id=487X782&url=http%3A%2F%2Fwww.techfest.org%2Fcompetitions%2Ftorque%2Fsolarsplash%2F

i am using 4700 micro farad capacitor to charge from  3 solar cell connected in paralle each of  2volts at 150 mA. i have a dc motor and when i connect this to it isnt providing sufficient torque . what should i do. also i dont know about any mechanism to cross a tunnel which is on the track where no light will be falling on solar pannel ... help !!


Are you using the limiting size of boat in the rules  ? Or have you thought smarter ? Have you looked in Instructables for solar engine ideas  ?

Have you built a test track, with the appropriate lighting ?

There's nothing to say you can't sit on the start line and save some charge into a capacitor BEFORE you set off.

Are you GETTING the power off the cells you think you should ? Have you measured the output, under the appropriate lighting ? 

How about someway of sucking power out of the solar cells? How would you build a MPPT charger ?


hey thanks for replying .
i have to use limited size of boat  i.e  25 cm * 20 cm * 20 cm .

i dont have (and cant have ) a test track here . all i can do is guess about the conditions there.

ya there isnt any rule that i cant charge my capacitors before i set off . but i am a complete amature in this feild and unaware of how to charge capacitors enough that i complete the track in one sprint . can u tell me some  mechanisms .

the size of solar pannel is limited and maximum o/p from my individual solar cell is 2 v at 150 mA . thus when 3 cells  are in parallel     will   give me  2v at 450 mA . i know this isn't sufficient but what is the solution ?   

u said sumthing like " mppt charger " i googled abut this and found thAt circiuts are too complex and would increase my boat weight .

reply !! 

I have given some clues to another team on this same problem, and I don't want to favour one team over another, so I'll have to keep this fairly "Socratic" (asking questions for you to ask questions) 

Why use the MAXIMUM size of boat ????

The rules say a 500W light, 600mm above the track. I REALLY would try and find a way of getting one to play with. You NEED measurements to work with REALLY REALLY need measurements.

Your boat is already too heavy - you said so in your question. A very simple MPPT circuit would not add much weight, and would get you power.

i know it would be unfair on your part to tell me every thing but u can atleat pitty on this 16 yr old  lad !! 

i know the team u given some clues. u suggested them external mirrors i suppose   it was indeed a smart thought - " hatss off to u " , but i dont think they would allow us to use them !

you suggested " pager motor  "  but i dont know if they are available here
but i found a similar thing  would this work ? should i buy

Operating Voltage -1.2V - 4.8V DC
Current @ 2.2 V - 145mA (No Load)
Current @ 4.8 V - 150mA (No Load)

Mini Solar Motor - Bullet 

i tried to  find a MPPT circuit on google but all i got was large and weird looking circuit . if u know any such simple circuit plzz send me the link or post it here

about smaller boat size :
i tried  a base with 15 * 10 * 5 cm but it couldnt withstand my solar cells and motors  weight . i  am using  thermocol for my base !

also wanted to know about capacitors .  should i use a large capacitoe  1 F 5.5 v . ?

Pager motors ?

Go down to your local mobile phone repair district and get talking.

oh will try . but please guide my project .

i will give u my current project status .

i have a " base "  to work on  , a geared motor also have a dc motor

i tried to build millers solar engine but my motor isnt working .

i have a water as well as air  propeller  .

3 solar cells .        dats all      
" where should i start from .. please  guide  "    

You need MEASUREMENTS from your cells to work out what you have to play with - there is no point fitting a 3/4 W motor, you just ain't going to get that kind of power from your cells. Are you ?

Your motor is too heavy, your boat is therefore too big. Post a picture of your boat. 


my boat is quite light ! it weighs not more then 150 gms . i have attached images . it is not complete.

a dc toy motor  i have is very light approx 20 gms .

what should be my next step ?

Measure your cell output under realistic conditions.

i will get a light today and measure the o/p . i will give u the observations tomorow.
by d way happy new year in advance !

Good luck with the tests, I think they will be a very sobering wakeup call for you about the available energy. 

Happy New year to you too.


sory for not replying yesterday, i was out of town for a celebration .
i got my readings , andthey are enlightning !
i am getting 3 volts at 30 mA from my complete pannel .

now wats next ?

hey i would like to correct my readings : i tested my pannels in good sunlight and my o/p is :
3 volts at 150 mA !  so power is approx  0.45 Wats      

They do what they say on the box. My ENTIRE point is you MUST measure them under the simulated lighting.

i dont know whats wrong with my pannels . i measured at afternoon in bright sunlight it gave 140 mA or so.

i simulated the lighting in the folownig way :  i coudnt get 300 watts halogen so got a 30 Watt bright light .

under this light my o/p is only 5 mA . so i can expext  that under 300 wats light i will get atleast  5 to 7 times more current  i.e only 30 mA .

I had a very nasty feeling you'd find that. Its not at all surprising, and I suspect you won't be the only one surprised to discover it at the water tank.

Thus, I say again, keep your boat small, narrow, and long, for the best speed/ drag. Or make a catamaran ? 

SOLAR panels are DESIGNED to work with sunlight, funnily enough - and 1000W/sq metre is considerably more optical energy than a 500W Halogen can deliver !

ya , the fact is suprising !
i was also thinking of a catamarn as it will give more stability , and i can have a elevated platform to place my pannels which will increase energy .

i exprimented with narrow and long base , but the is its stability
(there are chances that my boat gets upside down ) .

i will workout for the best possible design latter but the first thing is to run my motor ! and keep it running even inside the tunnel !

That's why you have a keel and/or you're careful about the centre of gravity. Put the motor and weighty bits as low as possible in the boat. In clean water, you can get away with IMMERSING the motor directly. Drain it after a run, but its not like you need days of life from it.

Sounds like you're getting good ideas.


do u know any method by which i can keep my motor running inside the tunnel where no light will be falling on my pannels ? 

Take this to PM Mihir, we're running out of space to talk !!!!