Re: Need Circuit Design -- Cheap...

On Mon, 20 Apr 2009 10:46:16 -0500, John Fields
<jfields@xxxxxxxxxxxxxxxxxxxxx> wrote:

On Fri, 17 Apr 2009 19:13:17 -0400, Bob Thomas <bobtms@xxxxxxxxxxxx>
wrote:

I want to modify my X-10 Alarm system to trigger my camera's in my
home and what I thought was going to be a pretty easy project turned
out not so straight forward.

I am willing to pay a fair but moderate fee for a design that includes
the parts list needed and a schematic, I can do the rest.

It turns out that the only place in the DS7000 (X-10 Security) that
has any signial outside of the microcontroller it uses to indicate
that it is armed is a LED.

The Voltage on the LED when the Alarm is Off = +5VDC (LED is off)
The Voltage on the LED when the Alanm is On = +3VDC (LED is on)
The voltage on the LED when the alarm has been triggered alternates
between 3 and 5 +VDC as the LED flashes. (~100 times / minute fairly
even, fast flash on/off)

So those are the three conditions I have to work with for this.

Here is what I need:

Conditions:
1. When the LED comes on I need to Close a NO relay for about 1/4
second (SPST) and then the relay will need to open again and stay
open. (The 3VDC will still be on)

2. When the LED is Off I need to Close another NO relay for about 1/4
second (SPST) and then open again and stay that way until the LED
comes back on. (The 5VDC will still be on)

3. When the Alarm is trigered, Condition 1 will have happened, the LED
will be On and have been on since I Armed the system, but once
triggered, the same LED will start to Flash and will continue to flash
until I reset it. When this happens the relay's don't need to do
anything in fact, I don't want them to do anything, so basically this
flashing condition needs to be ignored. Condition 3 will only happen
when the systems is armed (Condition 1) and triggered.

The relay contacts will have less than 1.5 VDC at less that 10ma on
them.

Constraints:
- Any parts must work from +5VDC (or less), Chips, Relays, etc.
- The sense current used to tap in to the LED should be very low, I
have no idea how much current the LED driver from the microcontroller
can deal with.
- The Flashing condition must be ignored.
- My preference is that the relays be solid state, but if mechanical
is required that is ok.
- The parts should be as small as reasonable for me to be able to work
with. I want to make this all fit in the X-10 DS-7000 case and there
is some room in there but not a lot.
- No PIC's or other microtrollers used, I can do this with a PIC
myself but I want to share this with some other X-10 hobbyists who
don't have PIC experience or burners.
- This will not be a commercial product, I do not plan to sell it, you
may retain any rights to it as long as I can share it for free for
X-10 hobbyists only (You will be given credits of course). (If 10 are
ever made that would be 8 more than I am aware of...)

Overview of what will actually be going on:
1. I Arm my Alarm and the "On" relay will in essense push an ON button
on an X-10 remote control PCB. This will power on the Camera through
an X-10 Module.
2. A motion detector in the area of the camera will trigger the camera
to actually start to transmit images to an X-10 Device that will start
a SanDisk recorder to record.
3. After a set time with no motion all of this will stop.
4. It must be assumed that the X-10 Alarm also get triggered during
all of this since a security motion detector is covering the same area
as the camera motion detector.
5. After a set amount of time the X-10 Security System resets, but the
"Armed" light stays blinking until I reset it, this is one way to know
the system was triggered while I was not home.
6. If the X-10 Security is triggered again before the reset, the LED
still just blinks. (3-5 VDC)
7. When I disarm the system the "Armed" LED will go out. (5VDC)
8. The second relay (Off) will push the Off button on the remote PCB
and power down the camera system.

I have everything to do this but the control relay circuit.

Please please reply to WildBill47@xxxxxxxxxxx if you are interested in
this project.

Thanks

---
This should work: (View in Courier)

. +5V
. |
. +---+---+---------+------+----------+-[+10µF-]-GND
. | | | | |K |8
. [10K] | [Rt] [10K][1N4148] +---+---+
. | | | | | 2|_ Vcc |3
. |U1A| +-[100nF]-+------+-----O|T OUT|---+-----+
. VARM>--|--|+\ | 6| | | |K
. | | >-+ +5--[1M]--+---|TH 7555|[COIL][1N4001]
. +--|-/ | | 7|_ | | |
. | | | +--O|D | GND GND
. | GND | | +---+---+
. | | [200nF] |1
. | | | GND
. | | GND
. | |
. | | +5
. | | |
. | | +---------+-----+----------+-[+10µF-]-GND
. | | LM393 | | |K |8
. | | U1B [10K] [10K][1N4148 +---+---+
. | +--|-\ | | | 2|_ Vcc |3
. | | | >--+-[100nF]-+-----+-----O|T OUT|---+-----+
. +-------|--|+/ 6| | | |K
. | | +5--[1M]---+---|TH 7555|[COIL][1N4001]
. [39K] [Ct] | 7|_ | | |
. | | +--O|D GND | GND GND
. GND GND | +---+---+
. [200nF] |1
. | GND
. GND



The values of Rt and Ct will depend on the flash rate of the LED, so
post the rate and I'll post the values.

Relays are Hamlin HE721A0500.

Send the check to:

John Fields
8905 Bluegrass Drive
Austin, Texas 78759

---
Oops, hold the check...

JF
.

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