20 LED Chaser

I

IanW

Guest
Hello

Does anyone have a circuit diagram for a 20 LED chaser please? All the ones
I can find via Google seem to be about 10.

Thanks
Ian
 
"IanW" <spammenot@blah.com> wrote in message news:ge5d54$co5$1@aioe.org...
Hello

Does anyone have a circuit diagram for a 20 LED chaser please? All the
ones I can find via Google seem to be about 10.
Click to expand...
There are many solutions to your request Ian. Here is one possibility:
http://www.electronics-tutorials.ws/sequential/seq_6.html

You can also build two of the circuits you have already found and
alternately enable them to accomplish your goal.
 
IanW wrote:
Hello

Does anyone have a circuit diagram for a 20 LED chaser please? All the ones
I can find via Google seem to be about 10.

Thanks
Ian
Click to expand...
You can use cascaded 4017's to do it. See
http://focus.ti.com/lit/ds/symlink/cd4017b.pdf

Ed
 
On 2008-10-27, IanW <spammenot@blah.com> wrote:
Hello

Does anyone have a circuit diagram for a 20 LED chaser please? All the ones
I can find via Google seem to be about 10.
Click to expand...
use a 4047 wired as an astable multivibrator for the oscilator.
and a 4017 decade counter, clock the 4017 from pin 10 of the 4047
use pins 10 and 11 to select between two banks of 10 LEDs.

if you use high efficiency LEDs the whole thing will run off 3v with
just those two chips a resistor and a capacitor for the clock and two
resistors to control brightness.

Bye.
Jasen
 
"ehsjr" <ehsjr@NOSPAMverizon.net> wrote in message
news:sNvNk.871$Jv2.37@nwrddc01.gnilink.net...

You can use cascaded 4017's to do it. See
http://focus.ti.com/lit/ds/symlink/cd4017b.pdf
Click to expand...
Thanks for the link. Must admit I'm a bit of a newbie at this but the
circuit diagram I have for 10 LEDS is this:

http://www.free-circuit-diagrams.com/light-led/page-1/169/led-chaser

Any idea how you woudl modify that circuit to include a second cascaded
4017?

Thanks
Ian
 
On Tue, 28 Oct 2008 15:11:27 -0000, "IanW" <spammenot@blah.com> wrote:

"ehsjr" <ehsjr@NOSPAMverizon.net> wrote in message
news:sNvNk.871$Jv2.37@nwrddc01.gnilink.net...

You can use cascaded 4017's to do it. See
http://focus.ti.com/lit/ds/symlink/cd4017b.pdf

Thanks for the link. Must admit I'm a bit of a newbie at this but the
circuit diagram I have for 10 LEDS is this:

http://www.free-circuit-diagrams.com/light-led/page-1/169/led-chaser

Any idea how you woudl modify that circuit to include a second cascaded
4017?
Click to expand...
---
Yup!

news:bdmeg4hke2vgn039r3agut9dcu0npnf1hf@4ax.com

JF
 
"John Fields" <jfields@austininstruments.com> wrote in message
news:3nmeg4ls4ttlsmvbdq2gvdcsr0pum3rs5l@4ax.com...
On Tue, 28 Oct 2008 15:11:27 -0000, "IanW" <spammenot@blah.com> wrote:


"ehsjr" <ehsjr@NOSPAMverizon.net> wrote in message
news:sNvNk.871$Jv2.37@nwrddc01.gnilink.net...

You can use cascaded 4017's to do it. See
http://focus.ti.com/lit/ds/symlink/cd4017b.pdf

Thanks for the link. Must admit I'm a bit of a newbie at this but the
circuit diagram I have for 10 LEDS is this:

http://www.free-circuit-diagrams.com/light-led/page-1/169/led-chaser

Any idea how you woudl modify that circuit to include a second cascaded
4017?

---
Yup!

news:bdmeg4hke2vgn039r3agut9dcu0npnf1hf@4ax.com
Click to expand...
Hi. Is that meant to be a link to another thread only I can't read it?

Ian
 
"IanW" <spammenot@blah.com> schreef in bericht news:ge95nu$an5$1@aioe.org...
"John Fields" <jfields@austininstruments.com> wrote in message
news:3nmeg4ls4ttlsmvbdq2gvdcsr0pum3rs5l@4ax.com...
On Tue, 28 Oct 2008 15:11:27 -0000, "IanW" <spammenot@blah.com> wrote:


"ehsjr" <ehsjr@NOSPAMverizon.net> wrote in message
news:sNvNk.871$Jv2.37@nwrddc01.gnilink.net...

You can use cascaded 4017's to do it. See
http://focus.ti.com/lit/ds/symlink/cd4017b.pdf

Thanks for the link. Must admit I'm a bit of a newbie at this but the
circuit diagram I have for 10 LEDS is this:

http://www.free-circuit-diagrams.com/light-led/page-1/169/led-chaser

Any idea how you woudl modify that circuit to include a second cascaded
4017?

---
Yup!

news:bdmeg4hke2vgn039r3agut9dcu0npnf1hf@4ax.com

Hi. Is that meant to be a link to another thread only I can't read it?

Ian
Click to expand...
alt.binaries.schematics.electronic
28-10-2008

petrus bitbyter
 
"John Fields" <jfields@austininstruments.com> wrote in message
news:3nmeg4ls4ttlsmvbdq2gvdcsr0pum3rs5l@4ax.com...
On Tue, 28 Oct 2008 15:11:27 -0000, "IanW" <spammenot@blah.com> wrote:


"ehsjr" <ehsjr@NOSPAMverizon.net> wrote in message
news:sNvNk.871$Jv2.37@nwrddc01.gnilink.net...

You can use cascaded 4017's to do it. See
http://focus.ti.com/lit/ds/symlink/cd4017b.pdf

Thanks for the link. Must admit I'm a bit of a newbie at this but the
circuit diagram I have for 10 LEDS is this:

http://www.free-circuit-diagrams.com/light-led/page-1/169/led-chaser

Any idea how you woudl modify that circuit to include a second cascaded
4017?

---
Yup!
Click to expand...
That's fantastic thanks :)

Just a couple of questions:

- R3 (& R4) would be 330ohm as I plan to use a 9V PP3 battery and the LEDs
are 2V 20mA, but do I need 1 resistor for each of the 10 LEDs connected to
U2 or just the one (as in that circuit on free-circuit-diagrams.com)?

- I'm not sure I understand the bit of the schematic around C1 & R1. VCC is
presumably the V+ from the battery, but where is the V- negative rail?

Thanks
Ian
 
On Wed, 29 Oct 2008 15:57:17 -0000, "IanW" <spammenot@blah.com> wrote:

"John Fields" <jfields@austininstruments.com> wrote in message
news:3nmeg4ls4ttlsmvbdq2gvdcsr0pum3rs5l@4ax.com...
On Tue, 28 Oct 2008 15:11:27 -0000, "IanW" <spammenot@blah.com> wrote:


"ehsjr" <ehsjr@NOSPAMverizon.net> wrote in message
news:sNvNk.871$Jv2.37@nwrddc01.gnilink.net...

You can use cascaded 4017's to do it. See
http://focus.ti.com/lit/ds/symlink/cd4017b.pdf

Thanks for the link. Must admit I'm a bit of a newbie at this but the
circuit diagram I have for 10 LEDS is this:

http://www.free-circuit-diagrams.com/light-led/page-1/169/led-chaser

Any idea how you woudl modify that circuit to include a second cascaded
4017?

---
Yup!

That's fantastic thanks :)

Just a couple of questions:

- R3 (& R4) would be 330ohm as I plan to use a 9V PP3 battery and the LEDs
are 2V 20mA, but do I need 1 resistor for each of the 10 LEDs connected to
U2 or just the one (as in that circuit on free-circuit-diagrams.com)?
Click to expand...
---
Just the one, but it's 9 LEDs, not 10.

Matter of fact, since there'll only be one LED on at a time anyway, you
ought to be able to be able to connect the 18 LEDs remaining LEDs to
ground through a single resistor.
---

- I'm not sure I understand the bit of the schematic around C1 & R1. VCC is
presumably the V+ from the battery, but where is the V- negative rail?
Click to expand...
---
The little triangle at the bottom of R1 is battery minus.

C1R1 is the POR (Power-On Reset) circuit, and it works by
differentiating the positive-going edge of Vcc and using the resulting
spike to reset U2 and U3 so that only their Q0's will be hot on
power-up.

The latch, U1C U1D, though, can come up either SET or RESET, so either
LED1 or LED2 will be on when the sequence starts.

JF
 
"John Fields" <jfields@austininstruments.com> wrote in message
news:coqhg4tfaodou31anjf1oins22okgqh1ho@4ax.com...

- R3 (& R4) would be 330ohm as I plan to use a 9V PP3 battery and the LEDs
are 2V 20mA, but do I need 1 resistor for each of the 10 LEDs connected to
U2 or just the one (as in that circuit on free-circuit-diagrams.com)?

---
Just the one, but it's 9 LEDs, not 10.
Click to expand...
I thought it was 10 on each since the schematic shows Q0 to Q9 (presumably
that's the order in which the LEDs illuminate?) and their corresponding IC
pins. Should I leave one of those unconnected?

Regards
Ian
 
On Thu, 30 Oct 2008 00:46:24 -0000, "IanW" <spammenot@blah.com> wrote:

"John Fields" <jfields@austininstruments.com> wrote in message
news:coqhg4tfaodou31anjf1oins22okgqh1ho@4ax.com...

- R3 (& R4) would be 330ohm as I plan to use a 9V PP3 battery and the LEDs
are 2V 20mA, but do I need 1 resistor for each of the 10 LEDs connected to
U2 or just the one (as in that circuit on free-circuit-diagrams.com)?

---
Just the one, but it's 9 LEDs, not 10.

I thought it was 10 on each since the schematic shows Q0 to Q9 (presumably
that's the order in which the LEDs illuminate?) and their corresponding IC
pins. Should I leave one of those unconnected?
Click to expand...
---
No, just change the reference designation of LED2 to LED11, connect the
cathodes of the remaining 18 LEDs to the remaining 18 outputs of U2 and
U3, and connect all of their cathodes to ground through the one
resistor.

BUT... there's a big problem which I just noticed, and that's that if
LED1 and LED11 are operated at 20mA, then the internal CMOS voltage
drops will be too great for the logic to work properly when LED1 or
LED11 are on, and the whole thing will probably hang. 20mA is also too
high for the rest of the outputs, so the obvious solution is to use
high-efficiency LEDs. Something like an HLMP-4700 with a Vf of 1.7V at
2mA would be OK.


JF
 
On Thu, 30 Oct 2008 07:20:13 -0500, John Fields
<jfields@austininstruments.com> wrote:

Oops...

No, just change the reference designation of LED2 to LED11, connect the
cathodes of the remaining 18 LEDs to the remaining 18 outputs of U2 and
^^^^^^^^
Click to expand...
anodes

JF
 
On Wed, 29 Oct 2008 15:57:17 -0000, "IanW" <spammenot@blah.com> wrote:

"John Fields" <jfields@austininstruments.com> wrote in message
news:3nmeg4ls4ttlsmvbdq2gvdcsr0pum3rs5l@4ax.com...
On Tue, 28 Oct 2008 15:11:27 -0000, "IanW" <spammenot@blah.com> wrote:


"ehsjr" <ehsjr@NOSPAMverizon.net> wrote in message
news:sNvNk.871$Jv2.37@nwrddc01.gnilink.net...

You can use cascaded 4017's to do it. See
http://focus.ti.com/lit/ds/symlink/cd4017b.pdf

Thanks for the link. Must admit I'm a bit of a newbie at this but the
circuit diagram I have for 10 LEDS is this:

http://www.free-circuit-diagrams.com/light-led/page-1/169/led-chaser

Any idea how you woudl modify that circuit to include a second cascaded
4017?

---
Yup!

That's fantastic thanks :)

Just a couple of questions:

- R3 (& R4) would be 330ohm as I plan to use a 9V PP3 battery and the LEDs
are 2V 20mA, but do I need 1 resistor for each of the 10 LEDs connected to
U2 or just the one (as in that circuit on free-circuit-diagrams.com)?
Click to expand...
---
Here; on abse:

news:s7ijg4l896sq4gjajmetrkokbi2vetsk8n@4ax.com

JF
 
IanW wrote:
"ehsjr" <ehsjr@NOSPAMverizon.net> wrote in message
news:sNvNk.871$Jv2.37@nwrddc01.gnilink.net...


You can use cascaded 4017's to do it. See
http://focus.ti.com/lit/ds/symlink/cd4017b.pdf


Thanks for the link. Must admit I'm a bit of a newbie at this but the
circuit diagram I have for 10 LEDS is this:

http://www.free-circuit-diagrams.com/light-led/page-1/169/led-chaser

Any idea how you woudl modify that circuit to include a second cascaded
4017?

Thanks
Ian
Click to expand...
The diagram at
http://focus.ti.com/lit/ds/symlink/cd4017b.pdf
shows 3 4017's, not two. It uses the first 4017
to control LEDs 1 through 9, the second to control
LEDs 10 through 17, and the third to control
LEDS 18, 19 and 20.

I can email a jpg of the schematic for that circuit.

I will "draw" an ascii schematic below that shows
the interconnections required between the 4017 ICs.
It does not show the LED wiring - that wiring will
be described. LED wiring is very close to what is
shown at the url you posted for free circuits. You
can use the 4011 clock circuit from that page.

CLOCK +-----------------------------------------------+
| | +-----------+ +-----------+ |
| | | | | | |
| ---15---- | ---15---- | ---15---- |
| | | | | | | | | |
+----14 | | +---14 | | +---14 | |
| | IC1 | | | | IC2 | | | | IC3 | |
| +-13 | | | +-13 | | | +-13 | |
| | | | | | | | | | | | | | |
| | --3--11-- | | | --3--11-- | | | ---10---- |
| | | | | | | | | | | | | |
| | +-- | ----+ | | +-- | ----+ | | +-------+
| | | | | | | | |
| +--------+ | +--------+ | +--+--[15K]----+
| | /e | /e | |
| +-[1K]-| 2N3904 +-[1K]-| Gnd [C1]
| \c Q1 Q2 \c |
| | | +9V
+--------------------+-------------------+

How it works: At power on, C1 (.01uf) and the 15K resistor send
a (+) reset pulse to IC1, which forces pin 3 on (+). That in
turn resets IC2, which in turn resets 1C3, so all three 4017's
are set to 0 upon power on. There is _no_ LED connected to
pin 3 for IC2 or IC3, but there is an LED (LED1) connected to
IC1 pin 3. Clock pulses are applied to IC1 pin 14 and to the
collectors of both transistors. These transistors (both are
2N3904's, but you can use almost any NPN) will not pass the
clock pulses through to the emitter, until the base goes positive.

With each clock pulse, IC1 advances one count, lighting
LEDs 2,3,4,5,6,7,8 and 9 in sequence. The next clock pulse
extinguishes LED9 and causes pin 11 to go + . That places
+ on the base of Q1 and on pin 13 of IC1. With pin 13 positive,
IC1 is frozen until it gets a reset pulse. With the base
of Q1 +, the same clock pulse that moved IC1 causes IC2 to
increment from 0 to 1 and light LED 10. (Since there is no LED
connected to the count 0 pin (pin 3), IC2 must increment to 1
before it can light an LED.) IC2 is wired to LEDS 10 through
17, as mentioned earlier. It operates identically to IC1.

When IC2 places + on its pin 11, it places + on the base of Q2
and freezes as IC1 did. Because the base is +, Q2 can now pass
clock pulses to IC3, and it can advance. It lights LEDs
17, 18, 19 and 20 in sequence. At the next clock pulse it places
a plus on pin 10, which sends a reset pulse to IC1, and the entire
operation starts over.

_LED wiring recap:_
All 20 of the LED cathodes connect to a resistor (R3 at the url
you posted) - make it 3.3K and use the LEDs John recommended.
LEDs 1-9 connect to IC1 as shown on the url you posted. _NO_
LED is connected to pin 11 of IC1. LEDs 10-17 connect to
IC2. _NO_ LED is connected to pin 3 or pin 11 of IC2. Otherwise,
the LED wiring is the same as that shown at t6he url. LEDs
18, 19 and 20 are connected to IC3 pins 2, 4 and 7 respectively.

Ed
 
"John Fields" <jfields@austininstruments.com> wrote in message
news:jt6jg499vo183s5mn0d97qebaoafp0krmd@4ax.com...

No, just change the reference designation of LED2 to LED11, connect the
cathodes of the remaining 18 LEDs to the remaining 18 outputs of U2 and
U3, and connect all of their cathodes to ground through the one
resistor.

BUT... there's a big problem which I just noticed, and that's that if
LED1 and LED11 are operated at 20mA, then the internal CMOS voltage
drops will be too great for the logic to work properly when LED1 or
LED11 are on, and the whole thing will probably hang. 20mA is also too
high for the rest of the outputs, so the obvious solution is to use
high-efficiency LEDs. Something like an HLMP-4700 with a Vf of 1.7V at
2mA would be OK.
Click to expand...
I'll hopefully be able to get some 5mm superbright red low current LEDs
locally tomorrow. The catalog (Maplin) says they draw 2mA and have a forward
voltage max of 2.5V. So that should suit the 3.6K resistors at R1,3 & 4 in
your new schematic.

I have actually tried assembling the circuit on that
free-circuit-diagrams.com site, however it doesn't work properly. That is,
the LEDs just seem to flash randomly, some flickering very very briefly and
then one will stay lit for 2-3 seconds and it'll seem to lock up for a bit
before randomly flashing again. I wonder if this is because of the 20mA
LEDs?

Thanks for taking the time to help and explaining things :)

Regards
Ian
 
"ehsjr" <ehsjr@NOSPAMverizon.net> wrote in message
news:gVoOk.1402$Jv2.175@nwrddc01.gnilink.net...

The diagram at
http://focus.ti.com/lit/ds/symlink/cd4017b.pdf
shows 3 4017's, not two. It uses the first 4017
to control LEDs 1 through 9, the second to control
LEDs 10 through 17, and the third to control
LEDS 18, 19 and 20.

I can email a jpg of the schematic for that circuit.

I will "draw" an ascii schematic below that shows
the interconnections required between the 4017 ICs.
It does not show the LED wiring - that wiring will
be described. LED wiring is very close to what is
shown at the url you posted for free circuits. You
can use the 4011 clock circuit from that page.

CLOCK +-----------------------------------------------+
| | +-----------+ +-----------+ |
| | | | | | |
| ---15---- | ---15---- | ---15---- |
| | | | | | | | | |
+----14 | | +---14 | | +---14 | |
| | IC1 | | | | IC2 | | | | IC3 | |
| +-13 | | | +-13 | | | +-13 | |
| | | | | | | | | | | | | | |
| | --3--11-- | | | --3--11-- | | | ---10---- |
| | | | | | | | | | | | | |
| | +-- | ----+ | | +-- | ----+ | | +-------+
| | | | | | | | |
| +--------+ | +--------+ | +--+--[15K]----+
| | /e | /e | |
| +-[1K]-| 2N3904 +-[1K]-| Gnd [C1]
| \c Q1 Q2 \c |
| | | +9V
+--------------------+-------------------+

How it works: At power on, C1 (.01uf) and the 15K resistor send
a (+) reset pulse to IC1, which forces pin 3 on (+). That in
turn resets IC2, which in turn resets 1C3, so all three 4017's
are set to 0 upon power on. There is _no_ LED connected to
pin 3 for IC2 or IC3, but there is an LED (LED1) connected to
IC1 pin 3. Clock pulses are applied to IC1 pin 14 and to the
collectors of both transistors. These transistors (both are
2N3904's, but you can use almost any NPN) will not pass the
clock pulses through to the emitter, until the base goes positive.

With each clock pulse, IC1 advances one count, lighting
LEDs 2,3,4,5,6,7,8 and 9 in sequence. The next clock pulse
extinguishes LED9 and causes pin 11 to go + . That places
+ on the base of Q1 and on pin 13 of IC1. With pin 13 positive,
IC1 is frozen until it gets a reset pulse. With the base
of Q1 +, the same clock pulse that moved IC1 causes IC2 to
increment from 0 to 1 and light LED 10. (Since there is no LED
connected to the count 0 pin (pin 3), IC2 must increment to 1
before it can light an LED.) IC2 is wired to LEDS 10 through
17, as mentioned earlier. It operates identically to IC1.

When IC2 places + on its pin 11, it places + on the base of Q2
and freezes as IC1 did. Because the base is +, Q2 can now pass
clock pulses to IC3, and it can advance. It lights LEDs
17, 18, 19 and 20 in sequence. At the next clock pulse it places
a plus on pin 10, which sends a reset pulse to IC1, and the entire
operation starts over.

_LED wiring recap:_
All 20 of the LED cathodes connect to a resistor (R3 at the url
you posted) - make it 3.3K and use the LEDs John recommended.
LEDs 1-9 connect to IC1 as shown on the url you posted. _NO_
LED is connected to pin 11 of IC1. LEDs 10-17 connect to
IC2. _NO_ LED is connected to pin 3 or pin 11 of IC2. Otherwise,
the LED wiring is the same as that shown at t6he url. LEDs
18, 19 and 20 are connected to IC3 pins 2, 4 and 7 respectively.
Click to expand...
Hi Ed. That's a brilliant and very clear description :).

I think I understand the function of the two types of IC but I'm not sure
sure what the transistors are actually for? John's circuit doesn't feature
any - is that because U1C & U1D perform a similar function?

I have some breadboard, so am going to make both yours and John's circuits
and work out the component layout. Should be fun.

Thanks very much for your help
Ian
 
On Thu, 30 Oct 2008 23:56:28 -0000, "IanW" <spammenot@blah.com> wrote:

"John Fields" <jfields@austininstruments.com> wrote in message
news:jt6jg499vo183s5mn0d97qebaoafp0krmd@4ax.com...

No, just change the reference designation of LED2 to LED11, connect the
cathodes of the remaining 18 LEDs to the remaining 18 outputs of U2 and
U3, and connect all of their cathodes to ground through the one
resistor.

BUT... there's a big problem which I just noticed, and that's that if
LED1 and LED11 are operated at 20mA, then the internal CMOS voltage
drops will be too great for the logic to work properly when LED1 or
LED11 are on, and the whole thing will probably hang. 20mA is also too
high for the rest of the outputs, so the obvious solution is to use
high-efficiency LEDs. Something like an HLMP-4700 with a Vf of 1.7V at
2mA would be OK.

I'll hopefully be able to get some 5mm superbright red low current LEDs
locally tomorrow. The catalog (Maplin) says they draw 2mA and have a forward
voltage max of 2.5V. So that should suit the 3.6K resistors at R1,3 & 4 in
your new schematic.

I have actually tried assembling the circuit on that
free-circuit-diagrams.com site, however it doesn't work properly. That is,
the LEDs just seem to flash randomly, some flickering very very briefly and
then one will stay lit for 2-3 seconds and it'll seem to lock up for a bit
before randomly flashing again. I wonder if this is because of the 20mA
LEDs?

Thanks for taking the time to help and explaining things :)
Click to expand...
---
My pleasure! :)

I'm not familiar with that site; do you have a link to their simulator?

JF
 
"John Fields" <jfields@austininstruments.com> wrote in message
news:9dlkg49kpa9t8ouhdcl8au0pi1eebm0qr2@4ax.com...

I have actually tried assembling the circuit on that
free-circuit-diagrams.com site, however it doesn't work properly. That is,
the LEDs just seem to flash randomly, some flickering very very briefly
and
then one will stay lit for 2-3 seconds and it'll seem to lock up for a bit
before randomly flashing again. I wonder if this is because of the 20mA
LEDs?

Thanks for taking the time to help and explaining things :)

---
My pleasure! :)

I'm not familiar with that site; do you have a link to their simulator?
Click to expand...
Sorry I should have been more specific, I meant I assembled the 10 LED
chaser that I posted previously about:

http://www.free-circuit-diagrams.com/light-led/page-1/169/led-chaser

and it doesn't work properly.

Regards
Ian
 
"Jasen Betts" <jasen@xnet.co.nz> wrote in message
news:ge6kpt$895$1@reversiblemaps.ath.cx...
On 2008-10-27, IanW <spammenot@blah.com> wrote:
Hello

Does anyone have a circuit diagram for a 20 LED chaser please? All the
ones
I can find via Google seem to be about 10.

use a 4047 wired as an astable multivibrator for the oscilator.
and a 4017 decade counter, clock the 4017 from pin 10 of the 4047
use pins 10 and 11 to select between two banks of 10 LEDs.

if you use high efficiency LEDs the whole thing will run off 3v with
just those two chips a resistor and a capacitor for the clock and two
resistors to control brightness.
Click to expand...
Hi Jasen. Thanks for the schematic on abse, that looks good too and makes 3
circuits to try out :)

I guess I might be pushing my luck here, but any suggestions for a chaser
that will work regardless of the current that the LEDs require? I've mail
ordered some high eff LEDs, since my local electronics supplier didn't have
any in stock today, but there's more choice of size/colour/brightness with
normal LEDs.

Regards
Ian
 
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