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The Master

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Posts posted by The Master

  1. Hi Gallo 59, There is a very simple and economical way to make these sounds that you want, and even more if needed.

    Use an NE-555 chip and a 4017 counter chip, when the horn "button" is pressed, the NE-555 would pulse (determined by R x C)
    and that in turn would initiate a count pulse into the 4017 and from the outputs, say, set the timing at 2 Hz, and from the selected outputs
    of the 4017, you could simply put, "off the top of my head", say a darlington transistor on each output  biased on via, a say, 6K8 resistor 1/4
    watt driving the base of each of the darlington transistors, that would power a decent relay (do not forget the quench diode to de-spike the back emf off the relay coil) and perhaps, drive the relay coils off BD269, BD263 etc... Build in on some perf board or Vero board, choose good quality relays, say 500 ohms and I would suggest adding a 12 Volt zener diode to the input power supply, perhaps, being fed in via a 4.7 ohm 1/2 watt resistor, to protect the Ne555 & 4017 from spikes, Cheers, Jeff

  2. A quick look on Google for SBL 3045-PT led me to Digikey.

    http://www.digikey.com/product-detail/en/SBL3045PT/SBL3045PT-ND/1935315

    It is a SCHOTTKY Diode 45V 30A TO3P pkg (dual diode) classed as obsolete.

    A replacement was suggested as a SBL3030 PT .

    Cheers, Jeff
    aka, The Master
    ==============

  3. Hi Guys,  I have been able to find the following Panasonic manuals which may also
    be of interest to some of the members

    Panasonic  DVD Home DVD Home Theater Sound System  for SA-HT530-GCP Service manual and 
    for SB-HT530-GCP service and owners manuals


    (1)  SA-HT530-GCP_Service_Manual.pdf      14.8 MB  101 pages    zipped = 14.6 MB

    (2)  SA-HT530-GCP_USER_MANUAL.pdf    2.51 MB    36 pages    zipped = 2.31MB

    (3)  SB-WA530-EB_Service_Manual.pdf        2.12 MB    31 pages    zipped =  2.04MB

    so I guess that item (1) will not pass-on to the library ? 

    drop me an email and I can send it to you as required.

    Cheers, Jeff

      email:    [email protected]           


    post-16550-1427914432006_thumb.png

  4. Hi, I used to design security systems for several major alarm companies in Sydney, Australia from 1976-1982, so I suggest  you may wish to look at sample & hold type detection.    The I.C.s I used then are very much used today, only less expensive.

    That is to say, once a "sensor" a reed switch, a pressure mat, an ultrasonic or a microwave sensor has tripped its own output relay to report back to the actual alarm "box" the actual alarm must hold that signal, be it an on or off state device sensor and pass that detected signal on to another portion of the alarm, that holds the signal level (Hi or Lo) whatever and after a pre-determined time (set by you)  this is the entry time, then once that has expired, it then goes into an alarm on mode and passes a signal, (either Hi or Lo) what ever to trigger the siren or noise maker. Note you also need to have an exit time, giving the sensors time to settle and you time to leave the protected premises, of course  8)

    Typically mechanical bells make the loudest noise in Decibels than sirens ( volt for volt, watt for watt ), however piezo sounders are also a great noise maker requiring a relatively small current at , say 12Volts DC.  Sirens can be made using a garden variety NE555 ic also. 

    I designed a 4  IC. car alarm (back in 1980) which can be adapted as a house alarm, it uses 3 x CMOS HEF4001 IC and 1 x HEF4011 I.C., about 9 capacitors and some 1N4002 diodes, a relay and a transistor BC635 and about 15 resistors. 

    The circuit basically was some slow to operate flip-flops.  An extra siren was added - externally switching on via the relay.

    The relay also could operate another heavy duty air horn relay which made lots of Air Horn noise, but draws many amps.

    The noise making is up to you, these are just small suggestions and examples of where you can go with an alarm system done well.  You can use a few transistors, a few resistors and a few capacitors and make a oscillator siren. These are quite good. Plenty of circuits are around on the net for these.

    These companies I designed for  manufactured these like sausages, they were the company's most sought after product back then, they sold many 10's of  thousands and made lots of  $$$ , but for me, I just got paid for the one design job :( ..... Lesson learned...do not do anything that you are not going to get residual income for ( royalties ). (eg: like muso's and singers get paid these days) I have not made that mistake ever again !  :D

    Start ----------> turn key and activate alarm------> exit time ------->alarm sets after a pre-determined time, usually 20 seconds to 40 seconds. You decide what time is to be used, using a variable resistor or commonly known as a Pot (short for potentiometer). This exit time wil give the "system" time to settle and passively activate and do its quiet job, until woken.

    Sensor-----> sample & Hold cct------> entry time cct------> alarm condition detected cct-----> make noise --->- reset and re-arm

    Entry time gives you time to go inside and de-activate the alarm , quietly with a key or a numeric keypad... what ever.

    Typically all alarms should have a Gelcell battery (12V) with a constant low (milliamps) charger to top up the battery.

    Some suggestions using the ubiquitous NE-555 I.C.
    =========================================

    http://www.unitechelectronics.com/NE-555.htm#mercury-switched

    http://www.unitechelectronics.com/NE-555.htm#hi-lo-siren

    http://www.unitechelectronics.com/NE-555.htm#photoeye-alarm

    http://www.unitechelectronics.com/NE-555.htm#touch-switch

    http://www.unitechelectronics.com/NE-555.htm  <-- the whole page is here

    Hope this makes life easier for you.  Remember, keep it simple. :)

    Cheers, Jeff

  5. Hi Folks,  hope this info is useful to someone.
    I was searching for a similar item when I came across this LED unit.   It looks quite impressive however, it shows the LED's output in Candle power.
    I'm contemplating adding two of these babys as driving lights..... low current high power, as used on various aircraft as landing lights.  Cool  eh........ or  what?

    https://www.aircraftspruce.com/catalog/elpages/teledynelandinglight.php



       * Lamp Type: TIR Lens             * Bulb: PAR36                        * Product Technology: LED
       * Wattage: 30w                        * Voltage: 10.5V - 30V DC       * Rated Life: 5000hrs
       * Max Beam Candlepower (MBCP): 165,000                            * Maximum Overall Length (MOL): 2.75 inches
       * Bulb Diameter: 4.5 inches                                                    * Case Operating Temperature: 65

  6. Hi Hazel Anne M, 

    Having had quite a lot to do with "piezo" devices, it would seem at best all that you may derive from a single Piezo device is about 0.5 Volts, which in broad terms , is not really useful for much except being a sensor.  Around 1973,  I was involved in a special "secret" project that used many piezo devices (adhered) on a concrete floor as footstep sensors, it worked brilliantly as the sound of crushing sand (an ingredient of concrete) was detected very well, however it produced a mere 0.5V max.

    Having said that, in our kitchen here, we have natural gas cooking and we use a " piezo " gun to ignite the gas, this produces  a spark of over 1000 volts (so I am told) , I have never been curious enough to actually measure one, but that may be of some use.

    Thinking about that,  it reminds me of those eternal  words on the star ship Enterprise.."di-lithium" crystals.

    It would be nice if we could apply pressure to a crystal quartz rock and produce copious amounts of electricty  by just sheer pressure alone. The impact applied to a quartz crystal in a gas ignition gun produces this high spark voltage.

    Cheers, Jeff

  7. Hi Folks,
    Has anyone ever used a USB Webcam to provide a CVBS video output.
    As an idea, this would make a very cheap security monitor as most TVs have a
    Video IN ports. Resolution is reasonable considering.  Audio is not necessary.

    Having pulled a ROCK-2  Rock 1.3-Megapixel Web Cam P&P apart and photographed
    its CCD bits close-up, has anyone had the need or courage to have ever ventured down this path or perhaps
    had an experience with finding what pins are video out .

    Thx  Jeff

  8. Hi Mr Plumber,
    How many of what parts do you require, there is very little info
    on what you want,  where you are and where you want a delivery to.
    We sell many many electronic parts here, buy one, buy 1000's
    Visa. Mastercard. Amex. Diners Card Min card order AUD$20
    excluding freight. All cards attract a 4.16668% fee as we get
    slugged 4% by the card providers (All banks).

    [email protected]

    Located in Sydney, Australia
    Fax: +61 (0) 2 9603 8685
    Ph: +61 (0) 2 9820 3555
    http://www.unitechelectronics.com


  9. Hi Folks,
    is VERY deadly and once touched accidently it can at the very least make you break-dance from the shock or at the other end of the spectrum , it can kill you "stone dead" instantly.
    I have a page specifically directed at mains voltages, 240 Volts AC to be exact, which here in Australia


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