well, i've just bought my first car. 75 honda civic. the left indicator is broketed so i've decided to redesign both. i'm planning to use a 50% duty cycle 555 timer circut, the one with the 2 diodes. that will drive a relay. which will drive the lights.
the timer needs to be 2 Hz, can that be done?
I'm gonna try this motor today
http://www.dse.com.au/cgi-bin/dse.storefront/427aa0ae0272ef082740c0a87f9c0719/Product/View/P9004
it has more rpms and more torque @ highest efficiency.
Ok i've installed this motor
http://www1.jaycar.com.au/productView.asp?ID=YM2716&CATID=&keywords=motor&SPECIAL=&form=KEYWORD&ProdCodeOnly=&Keyword1=&Keyword2=&pageNumber=&priceMin=&priceMax=&SUBCATID=
the problem is that this motor is about half as...
n000 i fried the motor. It started to smoke, drove at close to full speed for 2 metres or so then smoked heavier, slowed down then stopped alltogether. It was good while itm lasted.
I'm buying a new motor today tho. Also rated at 12V I can't find any motors the same size that are rated at a...
The tie wrap used to hold it together but i glued the tire on instead. I should remove it, but it adds ghetto-ness lol.
I think the tires wil be fine (hopefully) if they wear out it think i'll just buy a new car :). I've tortured this one enough . ;D
Here's some pics of the completed car. It's literally too fast for it's own good ;D
I used a rellay and a bd139. the pcb is glued with hot glue to the frame of the car.
all the lifted pads are from the original 4 mosfets which controlled forward, and reverse. with 1 relay i can only have...
I'll just go with my best friend (bd139). never failed me. i'll connect the relay between the collector and the supply. no worries!
At tafe (turtiary and further education) we had a few practicles on setting the offset null on 741s. 9.5/10 times out of ten they don't work. lecturers blame it on...
the tires and motor are just fine. no funny smoke... yet
i found this car in the trash (had a blown cap) lol.
btw, i hate op-amps... the 741 is a menace to get working. sometimes it does sometimes it doesn't. i've tried various ones from differet manufacturers. damn common mode gain aint...
yea i could do that buffer idea. i could use a bd139, bd140 and a 3055. I think i'll just go with a relay tho. cheap and easy. I doubt silicone could conduct better than copper/steel connections inside the relay. Before the mosfet blew up it lost 3 or so volts across it anyways.
Is that because...
like one of those darlington pair things minus the extra 0.7V drop? HFE=HFE1*HFE2 :D
I was thinking thesame thing. if the HFE was say 400 i don't think i would have a problem.
I've decided to get a relay. All i gotta do is hook up an opamp with say a gain of 20 and the output will hit supply...
ok, I hooked up a potty and adjusted untill it went to 1/2 vout. the output resistance of that IC is approx 800ohms
is that enough to drive a 3055 without blowing it up?
ok. turns out that unknown transisor had a terminal going to the reverse controlling mosfet which isn't there anymore (I don't intend to replace it).
If i get rid of that transistor, the IC is outputing 2.2V (on, 0V off) when Vbatt is 8V, 2.0V (on, 0V off) when Vbatt is 16V The Ic's VCC runs off...