RE: Re: Hmevision ir transmitter

["Ian B" <Ian@xxxxxxx>]

No worries Frank

Not often you get too much advice!!

Back to the baby

Ian B

>-----Original Message-----
>From: Frank Mc Alinden [mailto:armagh@xxxxxxx]
>Sent: 01 June 2002 10:56
>To: ukha_d@xxxxxxx
>Subject: Re: [ukha_d] Re: Hmevision ir transmitter
>
>
>Hi Ian + Ian
>                   
I think i confused myself more than Andy . Anyway its
>probably better if only one person advises Andy . I will keep dabbling
with
>my idea for transmitting until  i get the bloody thing to
work.
>
>Frank Mc
> ----- Original Message -----
>From: "Ian B" <Ian@xxxxxxx>
>To: <ukha_d@xxxxxxx>
>Sent: Saturday, June 01, 2002 7:15 PM
>Subject: RE: [ukha_d] Re: Hmevision ir transmitter
>
>
>> Good catch on the design. It was late last night after a fun
>time with the
>> new baby.
>>
>> I agree about the recent post of messages being confusing to say
the
>least.
>> Your design is better than mine and I have set it up as a pdf
for
>simplicity
>> and recording at my end. I am still learning after all.
>>
>> Both of the designs achieve the same aim of zoned output
>controlled by one
>> of HV ports. I thought some of the previous discussion was
going
>off track
>a
>> bit and all that negative logic was horrid.
>>
>> As soon as I find out the path on the web server to my web site I
will
>post
>> the pdf's there but in the mean time here is another apology and
another
>4k
>> attachment. All down to playing primary domain controller removal
and it
>> deleted my accounts as well - dohh.
>>
>> Andy - sorry if all this is confusing and shout if anything (apart
from
>> everything, oh well, that as well) is unclear.
>>
>> A quick lesson on transistors!!
>> These other transistors we are talking about with the arrow
>going into the
>> base rather that out of it operate in a different way. You can
think of
>the
>> ones where the arrow goes out of the base BC182 etc. as having
>the turning
>> on power flow into the base and out of the emitter. The other ones
like a
>> BC327 etc. have the turning on power flow into the collector and
OUT of
>the
>> base. This is very simplistic and of course current is negligible
when
>> referring to the base. In both types the main flow of current when
the
>> device is active is from collector to base. Hopefully this makes
sense
>(and
>> I am correct).
>>
>> Ian B
>>
>> >-----Original Message-----
>> >From: Ian Davidson [mailto:ian@xxxxxxx]
>> >Sent: 01 June 2002 09:32
>> >To: ukha_d@xxxxxxx
>> >Subject: Re: [ukha_d] Re: Hmevision ir transmitter
>> >
>> >
>> >Hi Ian B
>> >
>> >If you wish to do it the way you suggest an easier circuit
would be
>> >
>> >http://galeforce9.dnsalias.org/dsc0_0069.jpg
>> >
>> >A few less components and current draw off the ports of HV
still
>> >well within
>> >the limits.
>> >
>> >As I've said I don't have HV (maybe one day!) but if the
members that do
>> >have it and require the IR say which port they would prefer to
use and
>the
>> >maximum ratings they would want to control then I'm sure we
could design
>a
>> >circuit with minimum components that most people even with
minimum
>> >electronics experience could build.
>> >
>> >At the moment things keep changing so I think any designs
should be
>shelved
>> >until a common goal is reached as to what is required, if not
the poor
>> >people trying to understand basic electronics from that last
batch of
>> >messages will be frightened off for life !!!
>> >
>> >Ian D
>> >
>> >----- Original Message -----
>> >From: "Ian B" <Ian@xxxxxxx>
>> >To: <ukha_d@xxxxxxx>
>> >Sent: Saturday, June 01, 2002 12:46 AM
>> >Subject: RE: [ukha_d] Re: Hmevision ir transmitter
>> >
>> >
>> >> Your circuit looks like I had in mind back in year dot.
I
>have sat down
>> >and
>> >> had a think about this and we have been leading you up
the garden path
>a
>> >> bit. Fun trip though wasn't it. Anyway, here are my
thoughts..........
>> >>
>> >> I have attached (for my sins) a very small pdf with the
circuit (not
>> >quite)
>> >> as I saw it in my minds eye.  Things have changed a
bit and the TR1
>codes
>> >> etc. no longer refer to the same transistors so pay
attention. After
>some
>> >> (considerable) thought I figure the best way to do this
is use Port C
>in
>> >> OUTPUT mode. According to the specs it can drive TTL and
CMOS. This
>means
>> >> LED's so enough current for us.
>> >>
>> >> In off state PortC must be all zeros and we don't care
what the IR out
>is
>> >> doing. In this state TR2 is not conducting so the LED's
are never on.
>> >>
>> >> Right, from the left ($^%!) we have a pull up resistor
connecting to a
>> >> tranny TR1. When HV transmits IR the base is pulled low
and the tranny
>> >stops
>> >> conducting. I assume here that HV switches the ground.
This in turn
>sends
>> >> the voltage through TR2 high. This is where the clever
zoning bit is.
>If
>> >> PortC pin x is high it drives the tranny TR2 base and the
voltage
>reaches
>> >> TR3 - zone ON. If however the PortC pin x was low the
voltage would
>never
>> >> reach TR3 and nothing happens. As soon as the voltage
reaches TR3 it
>> >> conducts and the LED's come on! Voila...... Obviously the
LED's on the
>> >right
>> >> would be as many as you want i.e. 8 in your case.
>> >>
>> >> Well, that's the theory anyway.
>> >>
>> >> There may be a better way round this but it is late and I
am tired
>> >(excuses
>> >> excuses).
>> >>
>> >> I hope this is helpful and that I have got it somewhere
near correct.
>> >>
>> >> Off for a midnight snack, have fun. Let me know if
the
>diagram and text
>> >are
>> >> rubbish.
>> >>
>> >> Ian B
>> >>
>> >> p.s. you owe me one for making me think!! ;-))
>> >>
>> >> >-----Original Message-----
>> >> >From: andy_powell_is [mailto:ukha@xxxxxxx]
>> >> >Sent: 31 May 2002 20:25
>> >> >To: ukha_d@xxxxxxx
>> >> >Subject: [ukha_d] Re: Hmevision ir transmitter
>> >> >
>> >> >
>> >> >
>> >> >Ok, I'll try again.... (this is an abridged
version!)
>> >> >
>> >> >I've got the original circuit working.. it was the
2N2222 that was..
>> >> >err dead.. replaced it and it's all ok now...
>> >> >
>> >> >The circuit now consists of the diagram at
>> >> >http://www.automated.it/homevision/HVIR2.jpg
but with the bit that
>> >> >says Homevision port removed...
>> >> >
>> >> >
>> >> >> I think I've read the relevant messages. IF I've
read them right
>> >> >
>> >> >There was a sudden rush of them, mainly due to my
lack of
>> >> >intelligence :P
>> >> >
>> >> >> port a o/p is via a PNP which means it will
source the o/p and give
>> >> >a +volts
>> >> >> supply.
>> >> >
>> >> >I've used the phrase before, and I'm going to use it
again, err,
>> >> >chicken soup...
>> >> >
>> >> >> This lunch I built up a simple circuit details
are here:
>> >> >> http://galeforce9.dnsalias.org/dsc0_0064.jpg
>> >> >
>> >> >Thanks, I've saved them for reference...
>> >> >
>> >> >> You only need the one transistor. It is ZTX651 I
had on the bench
>> >> >at work.
>> >> >
>> >> >Awwww, I have a big bag of 2N2222's and BC182's
:(
>> >> >
>> >> >
>> >> >> It will handling up to 2A and does not require
any form of
>> >> >heatsink. It is
>> >> >
>> >> >I've put a 1k resistor in from the power supply to
the collector of
>> >> >the first transistor and according to the Circuit
maker I'm pulling
>> >> >2.995ma (the 1k resistor appears to drop the current
from 32.5ma to
>> >> >2.995ma, apparently)... is that a problem? am I going
to upset
>> >> >homevision by putting that resistor in there? it
still works on the
>> >> >breadboard...
>> >> >
>> >> >Bearing in mind that this is only 1/8 of the circuit,
if I add 7 more
>> >> >am I going to pull too much current?
>> >> >
>> >> >> an e-line transistor and has a very low on
resistance. It will only
>> >> >take
>> >> >> about 1mA of current to drive it from
homevision. If the led's you
>> >> >use are
>> >> >> 20mA devices then each transistor will drive 100
of them. If this
>> >> >is OTT
>> >> >
>> >> >Phoaaaarrrrr!! 8 zones of 100 emitters :P
>> >> >
>> >> >> The circuit is wired just to show it working ie
the 10K resistor to
>> >> >the base
>> >> >> is connected to the 5V rail to simulate a 5v o/p
from HV.
>> >> >
>> >> >So the HV port A supplies +5v too?? This is the bit
I'm really unsure
>> >> >of... should I connect the base of the first emitter
to Homevisions A
>> >> >ports via a 10k resistor (one for each A port ie one
for A1, one for
>> >> >A2..etc)?
>> >> >
>> >> >
>> >> >> If you drop me your address Andy I'll stick it
in the post and you
>> >> >can
>> >> >> experiment with it. (It is no good to me !)
>> >> >
>> >> >I'll email it privately... :D
>> >> >
>> >> >
>> >> >>
>> >> >> In answer to an earlier question you are correct
that for current
>> >> >to flow it
>> >> >> needs to complete a circuit. When voltage is
applied to the base of
>> >> >a
>> >> >> transistor it flows through the base emitter
junction of the
>> >> >transistor to
>> >> >> ground.
>> >> >
>> >> >You've lost me with this. Where is this? is it that
it flows (in the
>> >> >circuit at the url above) to the second transistor
via it's emitter
>> >> >and off to the seond and then to the emitter of that
and hence to
>> >> >ground?
>> >> >
>> >> >
>> >> >> I hope I've explained things ok, I'm not the
best teacher, but if
>> >> >you are
>> >> >> unsure just ask.
>> >> >
>> >> >You're doing pretty well if you ask me...
>> >> >
>> >> >> Again so as not to offend the list if ANYONE
wants this topic off
>> >> >list just
>> >> >> say and it will be.
>> >> >
>> >> >I did ask and the suggestion was that quite a few
people are
>> >> >interested, not only that but that this was one of
the few on topic
>> >> >threads... :O
>> >> >
>> >> >Thanks for all your help
>> >> >
>> >> >
>> >> >Andy
>> >> >
>> >> >
>> >> >
>> >> >For more information: http://www.automatedhome.co.uk
>> >> >Post message: ukha_d@xxxxxxx
>> >> >Subscribe:  ukha_d-subscribe@xxxxxxx
>> >> >Unsubscribe:  ukha_d-unsubscribe@xxxxxxx
>> >> >List owner:  ukha_d-owner@xxxxxxx
>> >> >
>> >> >Your use of Yahoo! Groups is subject to
>> http://docs.yahoo.com/info/terms/
>> > >
>> > >
>> > >
>> >
>> >
>> > For more information: http://www.automatedhome.co.uk
>> > Post message: ukha_d@xxxxxxx
>> > Subscribe:  ukha_d-subscribe@xxxxxxx
>> > Unsubscribe:  ukha_d-unsubscribe@xxxxxxx
>> > List owner:  ukha_d-owner@xxxxxxx
>> >
>> > Your use of Yahoo! Groups is subject to
>http://docs.yahoo.com/info/terms/
>> >
>> >
>>
>>
>>
>>
>> For more information: http://www.automatedhome.co.uk
>> Post message: ukha_d@xxxxxxx
>> Subscribe:  ukha_d-subscribe@xxxxxxx
>> Unsubscribe:  ukha_d-unsubscribe@xxxxxxx
>> List owner:  ukha_d-owner@xxxxxxx
>>
>> Your use of Yahoo! Groups is subject to http://docs.yahoo.com/info/terms/
>>
>>
>>
>>
>> For more information: http://www.automatedhome.co.uk
>> Post message: ukha_d@xxxxxxx
>> Subscribe:  ukha_d-subscribe@xxxxxxx
>> Unsubscribe:  ukha_d-unsubscribe@xxxxxxx
>> List owner:  ukha_d-owner@xxxxxxx
>>
>> Your use of Yahoo! Groups is subject to http://docs.yahoo.com/info/terms/
>>
>>
>
>
>
>For more information: http://www.automatedhome.co.uk
>Post message: ukha_d@xxxxxxx
>Subscribe:  ukha_d-subscribe@xxxxxxx
>Unsubscribe:  ukha_d-unsubscribe@xxxxxxx
>List owner:  ukha_d-owner@xxxxxxx
>
>Your use of Yahoo! Groups is subject to http://docs.yahoo.com/info/terms/
>
>
>

Yahoo! Groups Sponsor

ADVERTISEMENT

For more information: http://www.automatedhome.co.uk
Post message: ukha_d@xxxxxxx 
Subscribe:  ukha_d-subscribe@xxxxxxx 
Unsubscribe:  ukha_d-unsubscribe@xxxxxxx 
List owner:  ukha_d-owner@xxxxxxx

Your use of Yahoo! Groups is subject to the Yahoo! Terms of Service.