Because pneumatic or mechanical delay switches with outdoor fitting kits
are extortionately expensive, I was wondering if anyone had a good
circuit for making my own...

Ideally a single button press should start a delay timer that activates a
light for a few minutes (to light the way from the garage to the house).

I'm happy enough with digital electronics but my analogue is weak.. it
seems like there should be a way to use mains only for this, with a triac
or SCR to switch the load (1000W) and maybe some sort of rectified feed
to a CR circuit to do the timing. But I'm sure there must be a better
way...

The issue of it being outdoors (basically replacing a dead pneumatic
supposed-to-be-weatherproof switch) is also a problem, but making a
sealed rainproof box with a suitably rated momentary switch shouldn't be
too difficult.

Any ideas?

(I've seen motorised timers in an earlier thread but they were 110V
and in the US - I'm in the UK on 240V 50Hz).

PCPaul wrote:
Because pneumatic or mechanical delay switches with outdoor fitting kits
are extortionately expensive, I was wondering if anyone had a good
circuit for making my own...

Ideally a single button press should start a delay timer that activates a
light for a few minutes (to light the way from the garage to the house).

I'm happy enough with digital electronics but my analogue is weak.. it
seems like there should be a way to use mains only for this, with a triac
or SCR to switch the load (1000W) and maybe some sort of rectified feed
to a CR circuit to do the timing. But I'm sure there must be a better
way...

The issue of it being outdoors (basically replacing a dead pneumatic
supposed-to-be-weatherproof switch) is also a problem, but making a
sealed rainproof box with a suitably rated momentary switch shouldn't be
too difficult.

Any ideas?

(I've seen motorised timers in an earlier thread but they were 110V
and in the US - I'm in the UK on 240V 50Hz).


Seems to me, PCPaul, you are basically wanting a motion sensor light
fitting with two movement sensors (one at the front door, one at the
garage door) and, maybe, multiply light fittings.

Is there nothing on the Commercial market that meets your needs?? (Why
re-invent the wheel...?)

Daniel
** Posted from http://www.teranews.com **

On Wed, 04 Jun 2008 20:13:20 +1000, Daniel wrote:

Seems to me, PCPaul, you are basically wanting a motion sensor light
fitting with two movement sensors (one at the front door, one at the
garage door) and, maybe, multiply light fittings.

Is there nothing on the Commercial market that meets your needs?? (Why
re-invent the wheel...?)


Well, there are a few reasons...

- The garage and house are a long way apart and on a different phase of
the mains, so running a wire between them would be difficult and
expensive.

- At the garage end the motion sensor would have to pick you up as you
went through a narrow alley (from either end) - so conventional PIRs that
detect you as you move across the beam aren't very good for that
application - I tried one there. To pick you up from either end would
need either two sensors or a true 180 degree sensor, which gets tricky,
and again puts the price up. There isn't enough height to mount the
sensor high but looking straight down, to scan both ends at once.

- commercial switches apart from the mass market '500W xenon floodlight
with PIR' are a silly price. Commercial weatherproof delay switches are
absolutely ridiculous.

- (and finally a major reason), it seems like a nice project to do to
start getting into mains/analogue circuitry...

PCPaul wrote:

On Wed, 04 Jun 2008 20:13:20 +1000, Daniel wrote:

- commercial switches apart from the mass market '500W xenon
floodlight with PIR' are a silly price. Commercial weatherproof delay
switches are absolutely ridiculous.

£10 in Focus !

- (and finally a major reason), it seems like a nice project to do to
start getting into mains/analogue circuitry...

A good enough reason. :-)

--
Best Regards:
Baron.

On Fri, 06 Jun 2008 22:03:30 +0100, Baron wrote:

PCPaul wrote:

On Wed, 04 Jun 2008 20:13:20 +1000, Daniel wrote:

- commercial switches apart from the mass market '500W xenon floodlight
with PIR' are a silly price. Commercial weatherproof delay switches are
absolutely ridiculous.

£10 in Focus !

For a PIR floodlight, yes. But for a weatherproof delay switch? You must
be looking at different shelves to me - more like £25 for a pneumatic
switch and another £20 for the outdoor kit for it...


- (and finally a major reason), it seems like a nice project to do to
start getting into mains/analogue circuitry...

A good enough reason. :-)

I thought you'd understand ;-)

PCPaul wrote:
Because pneumatic or mechanical delay switches
with outdoor fitting kits are extortionately expensive,

Given any thought to how you will make *yours* weatherproof?
Priced an appropriate enclosure and fittings?
Ever built anything along these lines
(low-voltage control / mains on the output)?

Ideally a single button press should start a delay timer
that activates a light

A solid-state relay seems like the easy way for a 1-time project.
Logic-level inputs and whatever-you-specify on the output.
A parametric search at your favorite parts vendor's site
should turn up a likely candidate.

for a few minutes
(to light the way from the garage to the house).

This is the way most folks get a delay of over a minute:
http://www.google.com/search?q=CD406...ator+datasheet

On Wed, 04 Jun 2008 15:38:52 -0700, JeffM wrote:

PCPaul wrote:
Because pneumatic or mechanical delay switches with outdoor fitting kits
are extortionately expensive,

Given any thought to how you will make *yours* weatherproof? Priced an
appropriate enclosure and fittings?

I have an IP56 momentary switch already.. but I need the delay trigger
and mains switching to go on the back of it.

Ever built anything along these
lines (low-voltage control / mains on the output)?


Yup, although quite a while ago. I did an Electronics Engineering
apprenticeship but after doing the basics took a very strong digital
route - so the analogue got a bit left behind. I'm also intimately
familiar with the UK Wiring Regs and have rewired whole houses, so mains
isn't too scary. It's the bit in the middle that I don't have at the tip
of my tongue.

If it *was* low voltage control, mains out I'd be OK. It's trying to do
it all just from mains without having to put a 5V DC supply in there that
I'm really after - hence trying to do it all with AC and high voltages.

Ideally a single button press should start a delay timer that activates
a light

A solid-state relay seems like the easy way for a 1-time project.
Logic-level inputs and whatever-you-specify on the output. A parametric
search at your favorite parts vendor's site should turn up a likely
candidate.

Like I said, can it be done without logic voltages? I vaguely recall a
single chip mains-CMOS levels regulator, but I was hoping to avoid even
that if possible. Is there no way to do it simply with AC-only
components? It seems like a simple enough task, basically a monostable
but working with mains voltage AC. And preferably solid state. I'm not
even that bothered about the precision. +/-20% is no problem at all.


for a few minutes
(to light the way from the garage to the house).

This is the way most folks get a delay of over a minute:
http://www.google.com/search?q=CD406...ator+datasheet

Cheers, I've used them. On the digital side I've done everything up to
and including designing a 6502 based controller with paged memory and a
homebrew touchpad. It's purely the AC electronics (rather than electrics)
side that I wanted to pick up more about... without studying it in depth!

I know I could buy PIRs off the shelf, or get an electronic or pneumatic
delay switch, but I fancy doing it as a small project instead.

On Tue, 03 Jun 2008 22:40:48 GMT, PCPaul wrote:

Because pneumatic or mechanical delay switches with outdoor fitting kits
are extortionately expensive, I was wondering if anyone had a good
circuit for making my own...

Ideally a single button press should start a delay timer that activates a
light for a few minutes (to light the way from the garage to the house).

I'm happy enough with digital electronics but my analogue is weak.. it
seems like there should be a way to use mains only for this, with a triac
or SCR to switch the load (1000W) and maybe some sort of rectified feed
to a CR circuit to do the timing. But I'm sure there must be a better
way...

The issue of it being outdoors (basically replacing a dead pneumatic
supposed-to-be-weatherproof switch) is also a problem, but making a
sealed rainproof box with a suitably rated momentary switch shouldn't be
too difficult.

Any ideas?

(I've seen motorised timers in an earlier thread but they were 110V
and in the US - I'm in the UK on 240V 50Hz).

---
View in Courier:


..MAINS-+--------------------------------[LOAD]-+----+
.. |R1 | |
.. [3000R] | |
.. | CR1 FODM [180R] |
.. O +-[1N4007]-+ 3053 | |
.. | | | R2 +-----+ | MT2
.. S1 | --O-|-[1N4007]-+--[30KR]--1|A MT|3-+ MT1
.. | | CR2 | | | /| Q1
.. | | |+ +-2|K MT|4----G |
.. | | [2000µF] | +-----+ |
.. | | CR3 |C1 | U1 |
.. +-|-[1N4007]-+--------+----------------+
.. | |
..MAINS--------+-[1N4007]-+
.. CR4

When S1 closes, the full-wave bridge CR1,CR2,CR3,CR4 charges C1
through R1 and triggers U1, a random-phase TRIAC driver optocoupler
through R2.

http://www.fairchildsemi.com/ds/FO/FODM3052_NF098.pdf

This causes the output of U1 to conduct, triggering Q1, a TRIAC chosen
to handle the mains voltage and the load current.

After C1 has been charged up and S1 opens, C1 then discharges through
R2, keeping the TRIAC driver triggered until the current in its LED
falls below 300µA. When that happens the driver's output will go
open-circuit and the Q1 will turn off with the next mains
zero-crossing.

Here's a little simulation so you can get a feel for the timing and
the values of components needed. Pay particular attention to the
wattages needed for R1 and R2!

Version 4
SHEET 1 880 680
WIRE 272 0 160 0
WIRE 400 0 336 0
WIRE 16 96 -64 96
WIRE 160 96 160 0
WIRE 160 96 96 96
WIRE 272 96 208 96
WIRE 400 96 400 0
WIRE 400 96 336 96
WIRE 576 96 400 96
WIRE -64 160 -64 96
WIRE 576 160 576 96
WIRE 400 176 400 96
WIRE -64 320 -64 240
WIRE 208 320 208 96
WIRE 208 320 -64 320
WIRE 272 320 208 320
WIRE 400 320 400 240
WIRE 400 320 336 320
WIRE 576 320 576 240
WIRE 576 320 400 320
WIRE 160 432 160 96
WIRE 272 432 160 432
WIRE 400 432 400 320
WIRE 400 432 336 432
WIRE 400 512 400 432
FLAG 400 512 0
SYMBOL voltage -64 144 R0
WINDOW 3 24 104 Invisible 0
WINDOW 123 0 0 Left 0
WINDOW 39 0 0 Left 0
SYMATTR InstName V1
SYMATTR Value SINE(0 350 50 0 0 0 500)
SYMBOL diode 272 112 R270
WINDOW 0 32 32 VTop 0
WINDOW 3 0 32 VBottom 0
SYMATTR InstName D1
SYMATTR Value MUR460
SYMBOL res 112 80 R90
WINDOW 0 0 56 VBottom 0
WINDOW 3 32 56 VTop 0
SYMATTR InstName R1
SYMATTR Value 3000
SYMBOL cap 384 176 R0
SYMATTR InstName C1
SYMATTR Value 2000E-6
SYMBOL res 560 144 R0
SYMATTR InstName R2
SYMATTR Value 30K
SYMBOL diode 272 16 R270
WINDOW 0 32 32 VTop 0
WINDOW 3 0 32 VBottom 0
SYMATTR InstName D2
SYMATTR Value MUR460
SYMBOL diode 336 304 R90
WINDOW 0 0 32 VBottom 0
WINDOW 3 32 32 VTop 0
SYMATTR InstName D3
SYMATTR Value MUR460
SYMBOL diode 336 416 R90
WINDOW 0 0 32 VBottom 0
WINDOW 3 32 32 VTop 0
SYMATTR InstName D4
SYMATTR Value MUR460
TEXT 406 480 Left 0 !.tran 200 uic


Also, that cap is going to be pretty pricey.

http://www.newark.com/jsp/search/bro...questid=209120
JF

On Sat, 07 Jun 2008 11:06:59 -0500, John Fields
wrote:


Also, that cap is going to be pretty pricey.

http://www.newark.com/jsp/search/bro...questid=209120

---
Here's a better deal:

http://search.digikey.com/scripts/Dk....dll?Selection

JF

On Sat, 07 Jun 2008 12:01:47 -0500, John Fields
wrote:

On Sat, 07 Jun 2008 11:06:59 -0500, John Fields
wrote:


Also, that cap is going to be pretty pricey.

http://www.newark.com/jsp/search/bro...questid=209120

---
Here's a better deal:

http://search.digikey.com/scripts/Dk....dll?Selection

---
Oops...
That didn't come out right.

Go to the Digi-Key website then find aluminum electrolytic capacitors
and narrow the search down to 2000 to 2400µF and 360 to 450V.

JF

On Sat, 07 Jun 2008 12:31:54 -0500, John Fields wrote:

On Sat, 07 Jun 2008 12:01:47 -0500, John Fields
wrote:

On Sat, 07 Jun 2008 11:06:59 -0500, John Fields
wrote:


Also, that cap is going to be pretty pricey.

http://www.newark.com/jsp/search/
browse.jsp;jsessionid=PYIT2ONBRZU42CXDUZ1G3PQ?N=50 0003+1001309+148378
+182171&Ntk=gensearch_001&Ntt=mallory&Ntx=&_reques tid=209120

---
Here's a better deal:

http://search.digikey.com/scripts/Dk....dll?Selection

---
Oops...
That didn't come out right.

Go to the Digi-Key website then find aluminum electrolytic capacitors
and narrow the search down to 2000 to 2400µF and 360 to 450V.


That circuit is more like it.. the random phase trigger simplifies things
somewhat. Wonder if I can just sample it ;-)

I guess the cap needs to be that big to keep the optocoupler LED lit for
100s or so..

Since I don't really need the isolation, is there a way to do it that
uses a scaled down RC circuit to switch a transistor based trigger
instead? I'd guess you could do that with a few uA instead of the 60mA
the optocoupler needs.

On Sun, 08 Jun 2008 09:21:49 GMT, PCPaul wrote:

On Sat, 07 Jun 2008 12:31:54 -0500, John Fields wrote:

On Sat, 07 Jun 2008 12:01:47 -0500, John Fields
wrote:

On Sat, 07 Jun 2008 11:06:59 -0500, John Fields
wrote:


Also, that cap is going to be pretty pricey.

http://www.newark.com/jsp/search/
browse.jsp;jsessionid=PYIT2ONBRZU42CXDUZ1G3PQ?N=5 00003+1001309+148378
+182171&Ntk=gensearch_001&Ntt=mallory&Ntx=&_reque stid=209120

---
Here's a better deal:

http://search.digikey.com/scripts/Dk....dll?Selection

---
Oops...
That didn't come out right.

Go to the Digi-Key website then find aluminum electrolytic capacitors
and narrow the search down to 2000 to 2400µF and 360 to 450V.


That circuit is more like it.. the random phase trigger simplifies things
somewhat. Wonder if I can just sample it ;-)

I guess the cap needs to be that big to keep the optocoupler LED lit for
100s or so..

---
180 seconds.
---

Since I don't really need the isolation, is there a way to do it that
uses a scaled down RC circuit to switch a transistor based trigger
instead?

---
Yeah, there is.

I thought about it after I posted the other circuit, but didn't get
around to updating it.

I'll get on it sometime today...
---


I'd guess you could do that with a few uA instead of the 60mA
the optocoupler needs.

---
The optocoupler only needs 5mA to start, and it'll keep the output
conducting until the LED current drops to 300µA.


JF