Sukhbinder

Hi guys, i just saw on the net at http://cgi.ebay.co.uk/Induction-Charged-LED-Torch-No-Batteries-Ever-NEW_W0QQitemZ8730468431QQcategoryZ117110QQcmdZViewItem a LED torch which used no batteries. I've seen such devices earlier also , they shake the torch to charge it up and it work for 15-20mins. Using a LED reduces the current drain. I got one like it at fair but it was a duplicate one with 2 3V lithium batteries powering it. There is a coil in it but not conected. I need to add a magnet but i need some one to suggest a way to store the charge. if i connect a capacitor to the coil, the cap will be charged a bit by the coil when i shake it but will it not also discharge through the coil when the torch is stationary. Also when the magnet moves in one direction and then in the other direction won't the direction of voltages generated be opposite (more like AC and don't Capacitors act as short circuit to AC voltages) I f one needs DC we need to rectify it but how to rectify small voltages with common diodes. How to store the charge and let the discharge be gradual as from my previous experieces if u connect an LED to a charged cap, the led gives a flash of light and then glows dimly until the cap is completly discharged. Any ideas for this? since i have the enclosure fitted with a single white LED, a reflector and a convex lens glass in the front, i may be able to make a working prototype with help from u guys. :D

madthug, if u want to use RGB or RBG leds remember that if u want white colour from them, u need to have equal intensities for each of the 3 colours. Keep in mind that different colour leds have different forward voltages which is minimum for red and maximum for blue. if to reduce the voltage u can control the intensity to an extent but i reccommend controlling the current through the led which is a lot more trickier. Generally u can use PWM methods to control the intensity but varying the average current through the device, but keep in mind that even i u reduce the led current to nearly half its value, the change in intensity is very small (they use this to reduce the power comsumption for battery driven LED indicators). ::)

Hi guys, i have an idea which me seema bit off to u. the concentric ring design is very good. What if the rings can be printed on a plastic film like PET. I got this idea from the way the contacts are made these days in membrane type keyboards. they use two printed plastic sheets with a spacer sheet in between. I have an vacuum deposition unit at my university, where i deposit aluminium contacts for my devices. A better alternate to this is to use commercially available ITO (indium tin oxide) coated PET sheets. can easily pattern the using PVC tape as mask and common chemicals. the PET is quite strong and the ITO coating is conductive in nature. i hope i'm not being to scientific. :D

Thanks for the links Audioguru. sukhbinder

Thanks Ante for your suggestion but could u provide me with a simpler solution using conventional easily available components. the problem is that i live in New Delhi INDIA and the maxim IC is not available here easily. we have mail order firms like RS components here but they charge a lot. If u don't have a circuit in mind, could u just tell me how to use the C4060 as a timer. i'll take care of the constant current charging and voltage cutoff. thanks again

hi guys, i just opened up a uniross photosprint battery charger which has 2 timer settings of 6 & 9 hrs. i found that they used a CD4060 for the timing. The CD4060 is a 14 stage ripple counter. Can any one suggest any circuit for a timer using this IC. I'm planning to make my own battery charger for NiCd and NiMh cells as i have quite a lot a lying around my home. i found the this charger quite impressive as it automatically cuts off the charging after the time duration and puts the cells to trickle charging. It has a dual led indicator which indicated red for charging and green for trickle charging. it supports 1-4 AAA or AA batteries or 2 9V batteries. If any one has a circuit for such type of chargers please tell me. thanx ;)

i agree with audioguru that the heater element can work out with both AC or DC. use any simple dc dimmer or motor controller circuit as suggested by audioguru. u can use a PWM based curcuit for it.

Hi Nura, nice circuit, even i came up with the same idea but i discarded it because the circuit elements (the relays and wire wound resistors made it quite bulky). The circuit if i'm right switches resistors in the circuit thereby reducing the voltage and contolling the fan speed. i would surly like to see ur version of the phase controller speed regulator, this one is a more efficient and compact choice. ;)

Hi, Need Schematic and Service Manual for Philips PM3206 15 MHz Dual Oscilloscope, found one at the junk dealer, works fine, just need to check out its calibration and timing setting. Can any one help me out. Mine is a 240V version. Thanks ;)

Thanks Guys i just got the number from the Philips distributor. the IC is AN7164 from panasonic (mathshushita). ;)

I just got a philips FW335 mini HiFi set from my cousin for repairs ( which i do as a hobby). The main power amp IC was blown to such an extent that i could not even get the number. can any one help me out with the IC number and its data sheet (i need to see why it blew up!) if anyone has its sevice manual the better it is. thanx. ;) The IC i'm looking for is a 12pin SIL IC with Vcc at pin 12 and ground at pin 9. The only part of the number i could get is AN (the IC is of the AN series).

Need data sheet for JFET BFW10,BFW11 thanx ;)

Thanks for the datasheet. I already had it with me, but thx anyway. i seem to have solved the problem, it seems that the technics guys had put a .01mfd cap across each contact of the main power switch for contact suppression. one side of the switch was not functioning which caused the cap to charge through the main transformer leading to a LC circuit. cleaning the switch contacts did the trick. the dead left channel was a disconnented main speaker contact at the back. thx for all ur help ;D

need schematic and manual for a sony MHC-RV22 mini HiFi component system. thanx

I'm not sure of it. the technics SA-370S is a deck and receiver with an output of 55W RMS per channel. it has a STK465A stereo amplifier IC. It has a Dolby B NR system with normal/FeCr/CrO2 tape selection and music selector system (AMS). it has independent treble and bass controls with loudness control and independent recording controls for left and right channels. It has auxilary inputs and phono inputs

Thanks for the data sheet :D

I'm looking for the datasheet of HA1392 audio amp ic from hitachi. thnx ;)

thanks i got the datasheet. :D

need datasheet for uPC1230H from NEC. thax :)

I need the schematoc for this old model Technics deck & receiver. The model number is SA-370S. TNX.

can any one tell me the advantages and disadvantages of MOSFET based amplifiers. now days a lot of products are in the market which r having MOSFET amps. some say that Mosfets get damaged easily and recommend IGBJTs. can any one help out with my query. :D

sorry for the delay in posting the reply. The Hitachi component number is TRK-9300W. Its a FM/SW2/SW1/MW radio cassette tape recorder with detachable speakers. i also got a schematic diagram of the set with its user manual. they have specified the IC as EA1010 stereo graphic equaliser IC and the same is given on the IC. ;)

the two terms flutter and flicker r used in 2 different systems. flicker is generally associated with the change in the picture tube intensity in a TV while flutter together with WOW (or v may say wow & flutter) r used for the slow and fast variations in the tape speed of an audio cassette player.

i'm looking for the datasheet of EA1010 graphic equaliser IC. i found the ic in a Hitachi stereo component system. i can neither find the IC or its datasheet. can any one help me out. if u have any other grahic equaliser IC for stereo use in mind, pls. tell me.

thanks for the datasheet. :D