Driver to drive?

On Sun, 22 Sep 2013 08:55:44 -0700, Jim Thompson
<To-Email-Use-The-Envelope-Icon@On-My-Web-Site.com> wrote:

On Sat, 21 Sep 2013 19:32:39 -0700, OldGuy <OldGuy@spamfree.com
wrote:

Looking for the simplest way to this.

AC powered 9V wall-wart or 9V battery powering a circuit.
9V battery is alkaline so is not charged by 9V AC supply.
Load is < 50 ma.

When AC is on, power from the AC to 9v PS.
AC off, power from 9V battery.
9V battery only supplies power when 9V AC is off.

The catch: the 9V AC PS output may be lower than the 9V battery or
visa versa.

So a simple two diode scheme will not fly.
Minimum parts and no relays.
Suggestions please.



--- news://freenews.netfront.net/ - complaints: news@netfront.net ---

From a previous SED thread, where an unregulated wall-wart was
involved...


http://www.analog-innovations.com/SED/PowerSwitching_Battery-Wallwart.pdf

If I understand your situation correctly, it might be as simple as
using a barrel connector with a built-in switch (from R/S, as I
remember buying them)...

http://www.analog-innovations.com/SED/PowerSwitching_OldGuy.pdf

If you have a more complex situation, like wall-wart hard-wired in
place, I have other solutions to detect that it's live and switch
accordingly.

...Jim Thompson
Click to expand...

Found the jack on the SparkFun site...

<https://www.sparkfun.com/products/119>

...Jim Thompson
--
| James E.Thompson | mens |
| Analog Innovations | et |
| Analog/Mixed-Signal ASIC's and Discrete Systems | manus |
| San Tan Valley, AZ 85142 Skype: Contacts Only | |
| Voice:(480)460-2350 Fax: Available upon request | Brass Rat |
| E-mail Icon at http://www.analog-innovations.com | 1962 |

I love to cook with wine. Sometimes I even put it in the food.
 
On Sat, 21 Sep 2013 19:32:39 -0700, OldGuy <OldGuy@spamfree.com>
wrote:

Looking for the simplest way to this.

AC powered 9V wall-wart or 9V battery powering a circuit.
9V battery is alkaline so is not charged by 9V AC supply.
Load is < 50 ma.

When AC is on, power from the AC to 9v PS.
AC off, power from 9V battery.
9V battery only supplies power when 9V AC is off.

The catch: the 9V AC PS output may be lower than the 9V battery or
visa versa.

So a simple two diode scheme will not fly.
Minimum parts and no relays.
Suggestions please.
Click to expand...

---
Version 4
SHEET 1 1172 680
WIRE 144 -32 -96 -32
WIRE 352 -32 240 -32
WIRE 608 -32 352 -32
WIRE 832 -32 704 -32
WIRE 656 64 656 32
WIRE 192 80 192 32
WIRE 352 80 352 -32
WIRE 192 192 192 160
WIRE 704 192 544 192
WIRE 832 192 832 -32
WIRE 832 192 784 192
WIRE -96 240 -96 -32
WIRE -16 240 -96 240
WIRE 128 240 64 240
WIRE 656 240 656 144
WIRE 544 288 544 192
WIRE 544 288 512 288
WIRE 592 288 544 288
WIRE -96 336 -96 240
WIRE -16 336 -96 336
WIRE 448 336 64 336
WIRE -96 384 -96 336
WIRE 832 384 832 192
WIRE -96 512 -96 464
WIRE 192 512 192 288
WIRE 192 512 -96 512
WIRE 352 512 352 160
WIRE 352 512 192 512
WIRE 512 512 512 384
WIRE 512 512 352 512
WIRE 656 512 656 336
WIRE 656 512 512 512
WIRE 832 512 832 464
WIRE 832 512 656 512
WIRE -96 592 -96 512
FLAG -96 592 0
SYMBOL res 80 224 R90
WINDOW 0 0 56 VBottom 2
WINDOW 3 32 56 VTop 2
SYMATTR InstName R1
SYMATTR Value 10k
SYMBOL pnp 240 32 M270
WINDOW 0 7 148 VLeft 2
WINDOW 3 31 174 VLeft 2
SYMATTR InstName Q1
SYMATTR Value 2N3906
SYMBOL npn 128 192 R0
SYMATTR InstName Q3
SYMATTR Value 2N3904
SYMBOL res 176 64 R0
SYMATTR InstName R3
SYMATTR Value 1k
SYMBOL voltage -96 368 R0
WINDOW 3 24 96 Invisible 2
WINDOW 123 0 0 Left 2
WINDOW 39 0 0 Left 2
SYMATTR Value PULSE(0 9 1 1u 1u 1 2)
SYMATTR InstName V1
SYMBOL res 336 64 R0
WINDOW 0 40 47 Left 2
SYMATTR InstName R4
SYMATTR Value 180
SYMBOL pnp 608 32 R270
WINDOW 0 7 148 VLeft 2
WINDOW 3 31 174 VLeft 2
SYMATTR InstName Q2
SYMATTR Value 2N3906
SYMBOL npn 592 240 R0
SYMATTR InstName Q5
SYMATTR Value 2N3904
SYMBOL res 672 48 M0
SYMATTR InstName R5
SYMATTR Value 1k
SYMBOL voltage 832 368 M0
WINDOW 3 24 96 Invisible 2
WINDOW 123 0 0 Left 2
WINDOW 39 0 0 Left 2
SYMATTR Value 9
SYMATTR InstName V2
SYMBOL npn 448 288 R0
SYMATTR InstName Q4
SYMATTR Value 2N3904
SYMBOL res 80 320 R90
WINDOW 0 0 56 VBottom 2
WINDOW 3 32 56 VTop 2
SYMATTR InstName R2
SYMATTR Value 100k
SYMBOL res 800 176 R90
WINDOW 0 0 56 VBottom 2
WINDOW 3 32 56 VTop 2
SYMATTR InstName R6
SYMATTR Value 10k
TEXT -80 544 Left 2 !.tran 10
TEXT -56 424 Left 2 ;WALL-WART
TEXT 696 424 Left 2 ;BATTERY
TEXT 360 168 Left 2 ;LOAD
TEXT 32 544 Left 2 ;John Fields
TEXT 32 576 Left 2 ;22 September 2013

--
JF
 
On 9/21/2013 10:45 PM, Spehro Pefhany wrote:
Someone has a very evil sense of humor:-

http://i.imgur.com/ylGdaGn.jpg?1


Best regards,
Spehro Pefhany
Click to expand...

Fighting evil? There's an app for that. ;)

Cheers

Phil Hobbs

--
Dr Philip C D Hobbs
Principal Consultant
ElectroOptical Innovations LLC
Optics, Electro-optics, Photonics, Analog Electronics

160 North State Road #203
Briarcliff Manor NY 10510 USA
+1 845 480 2058

hobbs at electrooptical dot net
http://electrooptical.net
 
On Sun, 22 Sep 2013 09:51:19 -0700, Jim Thompson
<To-Email-Use-The-Envelope-Icon@On-My-Web-Site.com> wrote:

On Sun, 22 Sep 2013 08:55:44 -0700, Jim Thompson
To-Email-Use-The-Envelope-Icon@On-My-Web-Site.com> wrote:

On Sat, 21 Sep 2013 19:32:39 -0700, OldGuy <OldGuy@spamfree.com
wrote:

Looking for the simplest way to this.

AC powered 9V wall-wart or 9V battery powering a circuit.
9V battery is alkaline so is not charged by 9V AC supply.
Load is < 50 ma.

When AC is on, power from the AC to 9v PS.
AC off, power from 9V battery.
9V battery only supplies power when 9V AC is off.

The catch: the 9V AC PS output may be lower than the 9V battery or
visa versa.

So a simple two diode scheme will not fly.
Minimum parts and no relays.
Suggestions please.



--- news://freenews.netfront.net/ - complaints: news@netfront.net ---

From a previous SED thread, where an unregulated wall-wart was
involved...


http://www.analog-innovations.com/SED/PowerSwitching_Battery-Wallwart.pdf

If I understand your situation correctly, it might be as simple as
using a barrel connector with a built-in switch (from R/S, as I
remember buying them)...

http://www.analog-innovations.com/SED/PowerSwitching_OldGuy.pdf

If you have a more complex situation, like wall-wart hard-wired in
place, I have other solutions to detect that it's live and switch
accordingly.

...Jim Thompson

Found the jack on the SparkFun site...

https://www.sparkfun.com/products/119

...Jim Thompson
Click to expand...

Also on Digikey, with more technical detail...

<http://www.digikey.com/product-detail/en/PJ-202A/CP-202A-ND/252007>

Some may wonder how I made a symbol that can show as an open or closed
switch AND functionally perform that way...

PSpice can do conditional netlisting templates.

When the (text) character "|" is present (switch shows closed because
that "text" does the visual closing), the presence of that "text"
satisfies a conditional and it netlists as a wire... otherwise an open
;-)

I also do fuses, snip-out trim, and laser cut simulations that way.

...Jim Thompson
--
| James E.Thompson | mens |
| Analog Innovations | et |
| Analog/Mixed-Signal ASIC's and Discrete Systems | manus |
| San Tan Valley, AZ 85142 Skype: Contacts Only | |
| Voice:(480)460-2350 Fax: Available upon request | Brass Rat |
| E-mail Icon at http://www.analog-innovations.com | 1962 |

I love to cook with wine. Sometimes I even put it in the food.
 
On Sun, 22 Sep 2013 15:50:49 -0400, the renowned Phil Hobbs
<pcdhSpamMeSenseless@electrooptical.net> wrote:

On 9/21/2013 10:45 PM, Spehro Pefhany wrote:

Someone has a very evil sense of humor:-

http://i.imgur.com/ylGdaGn.jpg?1


Best regards,
Spehro Pefhany


Fighting evil? There's an app for that. ;)

Cheers

Phil Hobbs
Click to expand...

http://i.imgur.com/qw3wv.jpg




Best regards,
Spehro Pefhany
--
"it's the network..." "The Journey is the reward"
speff@interlog.com Info for manufacturers: http://www.trexon.com
Embedded software/hardware/analog Info for designers: http://www.speff.com
 
On Sun, 22 Sep 2013 10:08:45 -0400, Boris Mohar
<borism_void_@sympatico.ca> wrote:

On Sat, 21 Sep 2013 21:39:39 -0800, Robert Baer <robertbaer@localnet.com
wrote:

I STILL get error message "A News (NNTP) error has occurred:
Authentication Failed" (no quotes).
They do not want to answer any queries.
What the F is happening?

Same here. Sent them two emails to level2@teranews.com and no response.
Click to expand...

Just started working again for me today
 
On Sun, 22 Sep 2013 22:41:40 -0700, the renowned miso <miso@sushi.com>
wrote:

Actually Android dropped flash in 2012. Supposedly it can be added back.
Click to expand...

QNX appears to be promoting flash for fancy embedded GUIs.


Best regards,
Spehro Pefhany
--
"it's the network..." "The Journey is the reward"
speff@interlog.com Info for manufacturers: http://www.trexon.com
Embedded software/hardware/analog Info for designers: http://www.speff.com
 
nuny@bid.nes wrote:
On Sunday, September 22, 2013 7:08:45 AM UTC-7, Boris Mohar wrote:
On Sat,21 Sep 2013 21:39:39 -0800, Robert Baer<robertbaer@localnet.com

wrote:

I STILL get error message "A News (NNTP) error has occurred:

Authentication Failed" (no quotes).

They do not want to answer any queries.

What the F is happening?

Same here. Sent them two emails to level2@teranews.com and no
response.

http://www.teranews.net/systemstatus.html

System Status

Current Status: We recently had to repair several backend servers.
Click to expand...

Old articles were lost, but all current articles should arrive complete

from this point on. We are offering all paying users a 7 day credit.

Please click here to apply the 7 days. Please do not email us requesting

credit.
Mark L. Fergerson
Click to expand...
That looks like an exact copy of their response at least 3 times
before in the past..and the articles (pointed to by the BabyBird
GooGull) did not make it clear as to WHEN (except for year) and for HOW
LONG.
 
Peter McMullin wrote:
On Sun, 22 Sep 2013 10:08:45 -0400, Boris Mohar
borism_void_@sympatico.ca> wrote:

On Sat, 21 Sep 2013 21:39:39 -0800, Robert Baer<robertbaer@localnet.com
wrote:

I STILL get error message "A News (NNTP) error has occurred:
Authentication Failed" (no quotes).
They do not want to answer any queries.
What the F is happening?

Same here. Sent them two emails to level2@teranews.com and no response.

Just started working again for me today
Thanks, will re-try.
Click to expand...
 
Phil Hobbs wrote:
On 9/21/2013 10:45 PM, Spehro Pefhany wrote:

Someone has a very evil sense of humor:-

http://i.imgur.com/ylGdaGn.jpg?1


Best regards,
Spehro Pefhany


Fighting evil? There's an app for that. ;)

Cheers

Phil Hobbs

Oh! Bamma!
Click to expand...
 
Re-writing your design goal, might read as follows...

Battery backup is disabled when AC powered DC source is not avail.
Battery power drain must be minimal and circuit as simple as possible for power fail backup. Either source may range from 9V by +/- 40%.

Discussion
=====
A reed relay would switch in 1ms, slower than solid state but can be held with a cap and a 12V coil can turn on with 8V worst case to disable the battery.

The external DC source will have a diode bridge & cap suitable for direct connect to load with battery disable to load with only a few mA drive and contact rating with no significant voltage drop @ 400mA

http://www.digikey.com/product-detail/en/HE722A1200/HE108-ND/133207
 
On Sat, 21 Sep 2013 19:32:39 -0700, OldGuy <OldGuy@spamfree.com>
wrote:

Looking for the simplest way to this.

AC powered 9V wall-wart or 9V battery powering a circuit.
9V battery is alkaline so is not charged by 9V AC supply.
Load is < 50 ma.

When AC is on, power from the AC to 9v PS.
AC off, power from 9V battery.
9V battery only supplies power when 9V AC is off.

The catch: the 9V AC PS output may be lower than the 9V battery or
visa versa.

So a simple two diode scheme will not fly.
Minimum parts and no relays.
Suggestions please.
Click to expand...

BTW, having recently gone through the thinking of a similar situation
(high-reliability and at maybe 100x or 1000x the current, but
basically the same concept), you might want to give some thought to
your actual requirements vis-a-vis various situations on either power
port.

In particular, are glitches of any concern?

Consider the "simple" solution with a relay- and input coming from a
big AC adapter. Unplug the barrel connector and you get a brief glitch
(maybe a millisecond or two) as the contacts transfer. If the AC power
fails or is switched off, you could get a 1-second glitch with voltage
out dropping to maybe a volt before the battery takes over.

In a pathological situation, the AC adapter output could drop to about
half a volt if it is very cold without the relay dropping out (the
spec says "must drop out" is 5% of rated voltage, IIRC), which would
likely be outside the operating range of whatever you've got this
connected to.
 
On Mon, 23 Sep 2013 08:19:22 -0700 (PDT), Anthony Stewart
<tony.sunnysky@gmail.com> wrote:

Re-writing your design goal, might read as follows...

Battery backup is disabled when AC powered DC source is not avail.
Click to expand...

---
I believe he wants the battery backup to be _enabled_ when the AC
powered DC source is not available.
---

Battery power drain must be minimal and circuit as simple as possible for power fail backup. Either source may range from 9V by +/- 40%.

Discussion
=====
A reed relay would switch in 1ms, slower than solid state but can be held with a cap and a 12V coil can turn on with 8V worst case to disable the battery.
Click to expand...

---
According to the OP - before you re-wrote his design goals - a relay
wasn't an option.

How has that changed?
---

The external DC source will have a diode bridge & cap suitable for direct connect to load with battery disable to load with only a few mA drive and contact rating with no significant voltage drop @ 400mA

http://www.digikey.com/product-detail/en/HE722A1200/HE108-ND/133207
Click to expand...

---
That relay has two form "A" contacts, when what the OP would need - if
he opted for a relay - would be one set of form "C" contacts.

According to your rewritten spec, the 9V source could vary by +/- 40%,
which would put the voltage low at 5.4V.

The relay's guaranteed minimum pickup voltage is 8V, so with 5.4V from
the source it probably wouldn't work.

Additionally, with a 9V input to the relay coil the current would be
16mA, about 5 times higher than your spec'ed "a few mA" drive.

--
JF
 
On Mon, 23 Sep 2013 11:21:35 -0500, John Fields
<jfields@austininstruments.com> wrote:

On Mon, 23 Sep 2013 08:19:22 -0700 (PDT), Anthony Stewart
tony.sunnysky@gmail.com> wrote:

Re-writing your design goal, might read as follows...

Battery backup is disabled when AC powered DC source is not avail.

---
I believe he wants the battery backup to be _enabled_ when the AC
powered DC source is not available.
Click to expand...

That's the way I read it too, after realizing, it's sort of like a
clock radio with battery back-up... AC goes away, battery keeps clock
on-time so you're not late for work ;-)

---

Battery power drain must be minimal and circuit as simple as possible for power fail backup. Either source may range from 9V by +/- 40%.

Discussion
=====
A reed relay would switch in 1ms, slower than solid state but can be held with a cap and a 12V coil can turn on with 8V worst case to disable the battery.

---
According to the OP - before you re-wrote his design goals - a relay
wasn't an option.

How has that changed?
---

The external DC source will have a diode bridge & cap suitable for direct connect to load with battery disable to load with only a few mA drive and contact rating with no significant voltage drop @ 400mA

http://www.digikey.com/product-detail/en/HE722A1200/HE108-ND/133207

---
That relay has two form "A" contacts, when what the OP would need - if
he opted for a relay - would be one set of form "C" contacts.

According to your rewritten spec, the 9V source could vary by +/- 40%,
which would put the voltage low at 5.4V.

The relay's guaranteed minimum pickup voltage is 8V, so with 5.4V from
the source it probably wouldn't work.

Additionally, with a 9V input to the relay coil the current would be
16mA, about 5 times higher than your spec'ed "a few mA" drive.
Click to expand...

...Jim Thompson
--
| James E.Thompson | mens |
| Analog Innovations | et |
| Analog/Mixed-Signal ASIC's and Discrete Systems | manus |
| San Tan Valley, AZ 85142 Skype: Contacts Only | |
| Voice:(480)460-2350 Fax: Available upon request | Brass Rat |
| E-mail Icon at http://www.analog-innovations.com | 1962 |

I love to cook with wine. Sometimes I even put it in the food.
 
On 9/23/2013 2:13 AM, Spehro Pefhany wrote:
On Sun, 22 Sep 2013 22:41:40 -0700, the renowned miso <miso@sushi.com
wrote:



Actually Android dropped flash in 2012. Supposedly it can be added back.

QNX appears to be promoting flash for fancy embedded GUIs.


Best regards,
Spehro Pefhany
Click to expand...
Yes, Blackberry and Windows are the last holdouts on rendering flash,
but just for the browser as far as I know. They are using that variant
of Qt (name escapes me) for the GUI.
 
on 9/22/2013, John Fields supposed :
On Sat, 21 Sep 2013 19:32:39 -0700, OldGuy <OldGuy@spamfree.com
wrote:

Looking for the simplest way to this.

AC powered 9V wall-wart or 9V battery powering a circuit.
9V battery is alkaline so is not charged by 9V AC supply.
Load is < 50 ma.

When AC is on, power from the AC to 9v PS.
AC off, power from 9V battery.
9V battery only supplies power when 9V AC is off.

The catch: the 9V AC PS output may be lower than the 9V battery or
visa versa.

So a simple two diode scheme will not fly.
Minimum parts and no relays.
Suggestions please.


---
Version 4
SHEET 1 1172 680
WIRE 144 -32 -96 -32
WIRE 352 -32 240 -32
WIRE 608 -32 352 -32
WIRE 832 -32 704 -32
WIRE 656 64 656 32
WIRE 192 80 192 32
WIRE 352 80 352 -32
WIRE 192 192 192 160
WIRE 704 192 544 192
WIRE 832 192 832 -32
WIRE 832 192 784 192
WIRE -96 240 -96 -32
WIRE -16 240 -96 240
WIRE 128 240 64 240
WIRE 656 240 656 144
WIRE 544 288 544 192
WIRE 544 288 512 288
WIRE 592 288 544 288
WIRE -96 336 -96 240
WIRE -16 336 -96 336
WIRE 448 336 64 336
WIRE -96 384 -96 336
WIRE 832 384 832 192
WIRE -96 512 -96 464
WIRE 192 512 192 288
WIRE 192 512 -96 512
WIRE 352 512 352 160
WIRE 352 512 192 512
WIRE 512 512 512 384
WIRE 512 512 352 512
WIRE 656 512 656 336
WIRE 656 512 512 512
WIRE 832 512 832 464
WIRE 832 512 656 512
WIRE -96 592 -96 512
FLAG -96 592 0
SYMBOL res 80 224 R90
WINDOW 0 0 56 VBottom 2
WINDOW 3 32 56 VTop 2
SYMATTR InstName R1
SYMATTR Value 10k
SYMBOL pnp 240 32 M270
WINDOW 0 7 148 VLeft 2
WINDOW 3 31 174 VLeft 2
SYMATTR InstName Q1
SYMATTR Value 2N3906
SYMBOL npn 128 192 R0
SYMATTR InstName Q3
SYMATTR Value 2N3904
SYMBOL res 176 64 R0
SYMATTR InstName R3
SYMATTR Value 1k
SYMBOL voltage -96 368 R0
WINDOW 3 24 96 Invisible 2
WINDOW 123 0 0 Left 2
WINDOW 39 0 0 Left 2
SYMATTR Value PULSE(0 9 1 1u 1u 1 2)
SYMATTR InstName V1
SYMBOL res 336 64 R0
WINDOW 0 40 47 Left 2
SYMATTR InstName R4
SYMATTR Value 180
SYMBOL pnp 608 32 R270
WINDOW 0 7 148 VLeft 2
WINDOW 3 31 174 VLeft 2
SYMATTR InstName Q2
SYMATTR Value 2N3906
SYMBOL npn 592 240 R0
SYMATTR InstName Q5
SYMATTR Value 2N3904
SYMBOL res 672 48 M0
SYMATTR InstName R5
SYMATTR Value 1k
SYMBOL voltage 832 368 M0
WINDOW 3 24 96 Invisible 2
WINDOW 123 0 0 Left 2
WINDOW 39 0 0 Left 2
SYMATTR Value 9
SYMATTR InstName V2
SYMBOL npn 448 288 R0
SYMATTR InstName Q4
SYMATTR Value 2N3904
SYMBOL res 80 320 R90
WINDOW 0 0 56 VBottom 2
WINDOW 3 32 56 VTop 2
SYMATTR InstName R2
SYMATTR Value 100k
SYMBOL res 800 176 R90
WINDOW 0 0 56 VBottom 2
WINDOW 3 32 56 VTop 2
SYMATTR InstName R6
SYMATTR Value 10k
TEXT -80 544 Left 2 !.tran 10
TEXT -56 424 Left 2 ;WALL-WART
TEXT 696 424 Left 2 ;BATTERY
TEXT 360 168 Left 2 ;LOAD
TEXT 32 544 Left 2 ;John Fields
TEXT 32 576 Left 2 ;22 September 2013
Click to expand...

Interesting.
Thanks.
But you must sell 2N390x's. lol

Could Q4 be eliminated? Q5 base to Q3 collector?



--- news://freenews.netfront.net/ - complaints: news@netfront.net ---
 
Jim Thompson wrote on 9/22/2013 :
On Sat, 21 Sep 2013 19:32:39 -0700, OldGuy <OldGuy@spamfree.com
wrote:

Looking for the simplest way to this.

AC powered 9V wall-wart or 9V battery powering a circuit.
9V battery is alkaline so is not charged by 9V AC supply.
Load is < 50 ma.

When AC is on, power from the AC to 9v PS.
AC off, power from 9V battery.
9V battery only supplies power when 9V AC is off.

The catch: the 9V AC PS output may be lower than the 9V battery or
visa versa.

So a simple two diode scheme will not fly.
Minimum parts and no relays.
Suggestions please.



--- news://freenews.netfront.net/ - complaints: news@netfront.net ---

From a previous SED thread, where an unregulated wall-wart was
involved...


http://www.analog-innovations.com/SED/PowerSwitching_Battery-Wallwart.pdf

If I understand your situation correctly, it might be as simple as
using a barrel connector with a built-in switch (from R/S, as I
remember buying them)...

http://www.analog-innovations.com/SED/PowerSwitching_OldGuy.pdf

If you have a more complex situation, like wall-wart hard-wired in
place, I have other solutions to detect that it's live and switch
accordingly.

...Jim Thompson
Click to expand...

Wall-wart and battery hardwired in.
Wall-wart "off" when AC power fails.
No mechanical switches to control electronics state: on or off.
Always on.



--- news://freenews.netfront.net/ - complaints: news@netfront.net ---
 
Jim Thompson used his keyboard to write :
On Sun, 22 Sep 2013 09:51:19 -0700, Jim Thompson
To-Email-Use-The-Envelope-Icon@On-My-Web-Site.com> wrote:

On Sun, 22 Sep 2013 08:55:44 -0700, Jim Thompson
To-Email-Use-The-Envelope-Icon@On-My-Web-Site.com> wrote:

On Sat, 21 Sep 2013 19:32:39 -0700, OldGuy <OldGuy@spamfree.com
wrote:

Looking for the simplest way to this.

AC powered 9V wall-wart or 9V battery powering a circuit.
9V battery is alkaline so is not charged by 9V AC supply.
Load is < 50 ma.

When AC is on, power from the AC to 9v PS.
AC off, power from 9V battery.
9V battery only supplies power when 9V AC is off.

The catch: the 9V AC PS output may be lower than the 9V battery or
visa versa.

So a simple two diode scheme will not fly.
Minimum parts and no relays.
Suggestions please.



--- news://freenews.netfront.net/ - complaints: news@netfront.net ---

From a previous SED thread, where an unregulated wall-wart was
involved...


http://www.analog-innovations.com/SED/PowerSwitching_Battery-Wallwart.pdf

If I understand your situation correctly, it might be as simple as
using a barrel connector with a built-in switch (from R/S, as I
remember buying them)...

http://www.analog-innovations.com/SED/PowerSwitching_OldGuy.pdf

If you have a more complex situation, like wall-wart hard-wired in
place, I have other solutions to detect that it's live and switch
accordingly.

...Jim Thompson

Found the jack on the SparkFun site...

https://www.sparkfun.com/products/119

...Jim Thompson

Also on Digikey, with more technical detail...

http://www.digikey.com/product-detail/en/PJ-202A/CP-202A-ND/252007

Some may wonder how I made a symbol that can show as an open or closed
switch AND functionally perform that way...

PSpice can do conditional netlisting templates.

When the (text) character "|" is present (switch shows closed because
that "text" does the visual closing), the presence of that "text"
satisfies a conditional and it netlists as a wire... otherwise an open
;-)

I also do fuses, snip-out trim, and laser cut simulations that way.

...Jim Thompson
Click to expand...

SparkFun is fun but a little pricey except when it is the only place to
get what ya want.



--- news://freenews.netfront.net/ - complaints: news@netfront.net ---
 
On Monday, September 23, 2013 12:45:35 PM UTC-7, Baron wrote:
Jasen Betts Inscribed thus:



Thanks Ed. My problem is finding the transistor.
Click to expand...

What do you mean? Aren't there some TO-220 like transistors bolted to the metal plate (heat sink?)?


> > Tthe transistor may be internal to CM104

Those thin SIP packs are not likely to be able to drive light-bulbs.


Looking very closely at the photos, I would guess that the "CM"
designation is for "Connector Mating" ! There seems to be several
CMxxx designations printed on the board. If there are any numbers
printed on the actual device it may help to know.
Click to expand...

Most likely 100K ohm pull down resistors.
 
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