phone cordless power

epilot · Jan 30, 2006

hi friends,

today i had a wireless phone for repair and its handphone have a cordless
power circuit, it can be charged like a primary and secondary transformer
and since it use from high frequency system rather than that normal 50 or 60Hz transformers it must be smaller than that common transfers, but after taking the hand phone apart i saw that there is a very thin board with less than 15 number of coil and without any iron or Ferrite,

the freq maker(oscillator) for the primary has one transistor and a few other components,

it would be very ok if some could suggest any circuit for these nice smal transducers,

how know how many freq the oscillator produce in these devices?

do you think if i make a coil as secondary with different numbers then it can produce power without any other component?(the original secondary can produce more than 8V)

epilot · Jan 30, 2006

i tested the primary with an only 15 number of wire as a coil (as secondary) and could lighten a 6V lamp,

that is good and now i need for a circuit for primary(as an oscillator,ok?)

but i dont know what kind of circuit is ok?!
i have no info about primary coil freq and voltage( the primary is a 3 wired coil that has the third wire at center).

i can not to measure the primary voltage with a volt meter, it seems it produces a squre wave not a sinus wave,

i am wondered why there is no info or circuit about that transformer in the net because its structure seems to be simple(there is less than 20 components on the primary),
i dont know, perhaps my key words was not so right :roll:

justDIY · Jan 30, 2006

some basic ideas you could experiment with:

use a 555 based timer to switch current on and off into a large coil of wire (your primary)

use a second smaller coil with a rectifier, some capacitors and some sort of load, to see how much DC voltage you get

my idea is, the 555 timer switching current on and off into a coil will generate an electromagnetic field around the coil. another coil will absorb some of that energy through induction. then the rectifier and capacitors will smooth it into DC, and you can power your load with it.

of course, using something a bit less crude than a 555 timer, like a sawtooth or sinewave generator would produce better results, but a humble square wave might be enough to get you started

be sure to snub the back voltage your coils will generate when the input current is turned off

akg · Jan 30, 2006

i tested the primary with an only 15 number of wire as a coil (as secondary) and could lighten a 6V lamp,

hmm..that's a lot of power txed!!!(only with 15 coils, strong primary current??) will need a good experimentation..

epilot · Jan 31, 2006

akg said:
i tested the primary with an only 15 number of wire as a coil (as secondary) and could lighten a 6V lamp,

Click to expand...

hmm..that's a lot of power txed!!!(only with 15 coils, strong primary current??) will need a good experimentation..

really 14 number of wire for secondary :wink:
and 10 number for primary,(yes i know the difference between secondary and primary:lol: )

the phone is a Sanyo and i am agree that it is huge ampere drawer,
ho w can make a guess how many volt is in the primary coil?
i can not measure it with voltmeter

epilot · Jan 31, 2006

justDIY said:
some basic ideas you could experiment with:

use a 555 based timer to switch current on and off into a large coil of wire (your primary)

use a second smaller coil with a rectifier, some capacitors and some sort of load, to see how much DC voltage you get

my idea is, the 555 timer switching current on and off into a coil will generate an electromagnetic field around the coil. another coil will absorb some of that energy through induction. then the rectifier and capacitors will smooth it into DC, and you can power your load with it.

of course, using something a bit less crude than a 555 timer, like a sawtooth or sinewave generator would produce better results, but a humble square wave might be enough to get you started

be sure to snub the back voltage your coils will generate when the input current is turned off

please correct me if i am wrong:

i dont think i need for an ON and OFF timer, i think i need for an oscillator ,
and if i want to use from 555 IC then i need for 2 IC to CHANGE polarity very fast. with one IC i can not change polarity.

akg · Jan 31, 2006

epilot said:
please correct me if i am wrong:
i dont think i need for an ON and OFF timer, i think i need for an oscillator ,
and if i want to use from 555 IC then i need for 2 IC to CHANGE polarity very fast. with one IC i can not change polarity.

is ur primary an air core one. ?? if yes 555 can be used.
otherwise if the core is non-saturating type , then also 555 can be used.
further u can produce bipolar signal with 555 (not alone).

epilot · Jan 31, 2006

akg said:
epilot said:

please correct me if i am wrong:
i dont think i need for an ON and OFF timer, i think i need for an oscillator ,
and if i want to use from 555 IC then i need for 2 IC to CHANGE polarity very fast. with one IC i can not change polarity.

Click to expand...

is ur primary an air core one. ?? if yes 555 can be used.
otherwise if the core is non-saturating type , then also 555 can be used.
further u can produce bipolar signal with 555 (not alone).

what is relationship between core and 555

do you mean i use from 4 transistors on output of one 555 to produce a bipolar polarity? is there another way rather than 4 transistor output with 555?
a 555 can produce near 1.5A on output so i prefere one or 2 ONLY 555 without transistors in output

epilot · Jan 31, 2006

i want to make anothe search in the net but i dont know which key words are better,
can anyone help me please?

akg · Jan 31, 2006

epilot said:
what is relationship between core and 555

there is no relationship. as u know a 555 cannot directly produce bipolar signal. so if a iron core is there , it may saturate , and can get magnetized,siezing the reqd trans: action

do you mean i use from 4 transistors on output of one 555 to produce a bipolar polarity? is there another way rather than 4 transistor output with 555?

yes . a push pull amplifier config:

a 555 can produce near 1.5A on output so i prefere one or 2 ONLY 555 without transistors in output

:shock: :shock: 1.5A ?? (as per datasheet it's only 200ma max)

akg · Jan 31, 2006

epilot said:
i want to make anothe search in the net but i dont know which key words are better,
can anyone help me please?

u have said that the primary side has only few components . tried reading the part number of the transistor? is that the driver for the primary ? . if both ans is yes. then u can find the max current in the primary. , further draw the ckt dia and post , so that others can have a look .

epilot · Jan 31, 2006

a 555 can produce near 1.5A on output so i prefere one or 2 ONLY 555 without transistors in output

:shock: :shock: 1.5A ?? (as per datasheet it's only 200ma max)[/quote]

yes you are right

epilot · Jan 31, 2006

ok, here is the circuit, it has 2 transistor not one, an IC for reducing the voltage, i think to 12V but i am not sure.

it has a 2.6Ghz crystal sso it might to oscillate near 26 000 000 000 time per second, i think i am wrong becuse i dont know any transistor the could make oscillate so high :shock: ?! beside i never seen a crystal so high :shock:

what is your idea? who can explain the circuit?

epilot · Jan 31, 2006

i can not understand why there is a 2.56GHz crystal while 2 transistors can not oscillate more than 250MHz? really one is 100MHz and the other is 250MHz!

akg · Feb 1, 2006

epilot said:
i can not understand why there is a 2.56GHz crystal while 2 transistors can not oscillate more than 250MHz? really one is 100MHz and the other is 250MHz!

mmmmm.. need blessing from e'Gods'

epilot · Feb 2, 2006

mmmmm.. need blessing from e'Gods'[/quote]

where are electronic Gods?

Nigel Goodwin · Feb 2, 2006

epilot said:
mmmmm.. need blessing from e'Gods'

where are electronic Gods? [/quote]

It's probably very simple, it's NOT a 2.56GHz crystal, only a 2.56MHz one. As you already know, you don't get crystals that high.

However, the circuit is so badly drawn, and completely confusing to look at, that's it's hard to understand - draw it out properly and repost it!.

epilot · Feb 2, 2006

Nigel Goodwin said:
epilot said:

mmmmm.. need blessing from e'Gods'

Click to expand...

where are electronic Gods?

It's probably very simple, it's NOT a 2.56GHz crystal, only a 2.56MHz one. As you already know, you don't get crystals that high.

However, the circuit is so badly drawn, and completely confusing to look at, that's it's hard to understand - draw it out properly and repost it!.[/quote]

sorry Nigel, the circuit is drawn with circuit maker5 and i was not able to save it because the software is a demo version, so now i have a pic from it and can not proper it

if you or othere guys could say me if the circuit generates a square wave or a sine wave and why there is a 3 wire coil and if i can use from 2 wire coil , then i'll try to build one using another circuit.

thanks

akg · Feb 2, 2006

i suspect that it shld be sqwave , since it provides maximum flux change speed . so that more V is induced in secondary.

phone cordless power

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