Maker Pro
Maker Pro

Remote Turn-On

M

Mike DeAngelis

Jan 1, 1970
0
Hi,
Does anyone have a schematic, kit, or a complete product to sense a line
level audio signal and turn a remote power amplifier on? I have done all the
searches I can think of and have not found anything. These things can't be
that rare!!
Thanks...Mike DeAngelis
 
D

Deefoo

Jan 1, 1970
0
Mike DeAngelis said:
Hi,
Does anyone have a schematic, kit, or a complete product to sense a line
level audio signal and turn a remote power amplifier on? I have done all the
searches I can think of and have not found anything. These things can't be
that rare!!
Thanks...Mike DeAngelis

Maybe you could use a VOX, a voice activated switch often used in CB and ham
radio.

-- DF
 
P

Peter Bennett

Jan 1, 1970
0
Hi,
Does anyone have a schematic, kit, or a complete product to sense a line
level audio signal and turn a remote power amplifier on? I have done all the
searches I can think of and have not found anything. These things can't be
that rare!!
Thanks...Mike DeAngelis

In Amateur Radio, this would be called a "VOX circuit" (voice operated
transmit") Googling for that term will get lots of hits...
 
E

ehsjr

Jan 1, 1970
0
Mike said:
Hi,
Does anyone have a schematic, kit, or a complete product to sense a line
level audio signal and turn a remote power amplifier on? I have done all the
searches I can think of and have not found anything. These things can't be
that rare!!
Thanks...Mike DeAngelis


http://www.ramseyelectronics.com/

Put VS-1 in the search box.

It's a vox kit for $9.95. It can drive a 100 mA load, such as a relay,
which can turn the amplifier on/off.

Ed
 
P

Pooh Bear

Jan 1, 1970
0
Mike said:
Hi,
Does anyone have a schematic, kit, or a complete product to sense a line
level audio signal and turn a remote power amplifier on? I have done all the
searches I can think of and have not found anything. These things can't be
that rare!!

I doubt many ppl need to do it.

Why not design your own ? It isn't that difficult.

Graham
 
E

ehsjr

Jan 1, 1970
0
Pooh said:
ehsjr wrote:




100mA ! ???

You're kidding right ?

Graham

No. What it is about a 100 mA load that engenders your question?

Ed
 
J

John Fields

Jan 1, 1970
0
Hi,
Does anyone have a schematic, kit, or a complete product to sense a line
level audio signal and turn a remote power amplifier on? I have done all the
searches I can think of and have not found anything. These things can't be
that rare!!
 
M

Mike DeAngelis

Jan 1, 1970
0
The amp should turn on when an audio signal is present and turn off some
time (2 min.?) after the audio signal is not present.
...Mike
 
R

Rich Grise

Jan 1, 1970
0
The amp should turn on when an audio signal is present and turn off some
time (2 min.?) after the audio signal is not present.

Yeah, like they said, a VOX. "Voice-operated transmission".

It seems to google up pretty good.

Have Fun!
Rich
 
J

John Fields

Jan 1, 1970
0
The amp should turn on when an audio signal is present and turn off some
time (2 min.?) after the audio signal is not present.

---
OK. (view in Courier)

V+
+5V>-+--------+------+---------------+-----+---+ |
| | | | | | | COM
| | |R1 | | | +------+ |
| | [10k] | | | |K | O
| | | | | [4K7][DIODE] [COIL]- |
| | | | | | | | O-> |
| | | CR1 | | | +------+ |
| +---|-[1M]-+-[<1N4148]-+ |Rd | | | NO
|Rth | | | | [10K]<-|+\ | D
[10K]<-+--|+\ | R2 | | | >-+---G
| | >----+--[510K]---+---|----|-/ LM393 S
VIN>---[10K]-|-/ LM393 |+ | | U1B |
| | U1A [240µF]| | |
| | C1| | | |
GND>-+--------+------------------+---+-----+---------+


Do you need a circuit description?
 
J

John Fields

Jan 1, 1970
0
The amp should turn on when an audio signal is present and turn off some
time (2 min.?) after the audio signal is not present.

---
OK. (view in Courier)

V+
+5V>-+--------+------+---------------+-----+---+ |
| | | | | | | COM
| | |R1 | | | +------+ |
| | [10k] | | | |K | O
| | | | | [4K7][DIODE] [COIL]- |
| | | | | | | | O-> |
| | | CR1 | | | +------+ |
| +---|-[1M]-+-[<1N4148]-+ |Rd | | | NO
|Rth | | | | [10K]<-|+\ | D
[10K]<-+--|+\ | R2 | | | >-+---G
| | >----+--[510K]---+---|----|-/ LM393 S
VIN>---[10K]-|-/ LM393 |+ | | U1B |
| | U1A [240µF]| | |
| | C1| | | |
GND>-+--------+------------------+---+-----+---------+


Do you need a circuit description?

---
Oops... Discharging C1 through U1A's output transistor without some
sort of current limiting might hurt it. 200 ohms will limit the
current to about 20mA when C1 first starts to discharge and will
keep U1 safe.


V+
+5V>-+--------+------+---------------+-----+---+ |
| | |R1 | | | | COM
| | [10K] | | | +------+ |
| | | CR1 | | | |K | O
| | +-[<1N4148]-+ | | [4K7][DIODE] [COIL]- |
| | | | | | | | | O-> |
| | | [200] | | | +------+ |
| +---|-[1M]-+ | |Rd | | | NO
|Rth | | | | [10K]<-|+\ | D
[10K]<-+--|+\ | R2 | | | >-+---G
| | >----+--[510K]---+---|----|-/ LM393 S
VIN>---[10K]-|-/ LM393 |+ | | U1B |
| | U1A [240µF]| | |
| | C1| | | |
GND>-+--------+------------------+---+-----+---------+
 
E

ehsjr

Jan 1, 1970
0
John said:
The amp should turn on when an audio signal is present and turn off some
time (2 min.?) after the audio signal is not present.


---
OK. (view in Courier)

V+
+5V>-+--------+------+---------------+-----+---+ |
| | | | | | | COM
| | |R1 | | | +------+ |
| | [10k] | | | |K | O
| | | | | [4K7][DIODE] [COIL]- |
| | | | | | | | O-> |
| | | CR1 | | | +------+ |
| +---|-[1M]-+-[<1N4148]-+ |Rd | | | NO
|Rth | | | | [10K]<-|+\ | D
[10K]<-+--|+\ | R2 | | | >-+---G
| | >----+--[510K]---+---|----|-/ LM393 S
VIN>---[10K]-|-/ LM393 |+ | | U1B |
| | U1A [240µF]| | |
| | C1| | | |
GND>-+--------+------------------+---+-----+---------+


Do you need a circuit description?

C(harge)R(apidly)1 - clever! I would not have thought
of it.

Ed
 
J

John Fields

Jan 1, 1970
0
John said:
The amp should turn on when an audio signal is present and turn off some
time (2 min.?) after the audio signal is not present.


---
OK. (view in Courier)

V+
+5V>-+--------+------+---------------+-----+---+ |
| | | | | | | COM
| | |R1 | | | +------+ |
| | [10k] | | | |K | O
| | | | | [4K7][DIODE] [COIL]- |
| | | | | | | | O-> |
| | | CR1 | | | +------+ |
| +---|-[1M]-+-[<1N4148]-+ |Rd | | | NO
|Rth | | | | [10K]<-|+\ | D
[10K]<-+--|+\ | R2 | | | >-+---G
| | >----+--[510K]---+---|----|-/ LM393 S
VIN>---[10K]-|-/ LM393 |+ | | U1B |
| | U1A [240µF]| | |
| | C1| | | |
GND>-+--------+------------------+---+-----+---------+


Do you need a circuit description?

C(harge)R(apidly)1 - clever! I would not have thought
of it.
 
M

Mike DeAngelis

Jan 1, 1970
0
John,
Thanks allot. You are pretty good drawing with Courier. What would be
the device type used for driving the relay? Also, would any damage occur if
the input audio signal exceeds the rail voltage (5v)? In the application I
have in mind I believe the audio can reach 6 V RMS.
...Mike
John Fields said:
John said:
The amp should turn on when an audio signal is present and turn off some
time (2 min.?) after the audio signal is not present.


---
OK. (view in Courier)

V+
+5V>-+--------+------+---------------+-----+---+ |
| | | | | | | COM
| | |R1 | | | +------+ |
| | [10k] | | | |K | O
| | | | | [4K7][DIODE] [COIL]- |
| | | | | | | | O-> |
| | | CR1 | | | +------+ |
| +---|-[1M]-+-[<1N4148]-+ |Rd | | | NO
|Rth | | | | [10K]<-|+\ | D
[10K]<-+--|+\ | R2 | | | >-+---G
| | >----+--[510K]---+---|----|-/ LM393 S
VIN>---[10K]-|-/ LM393 |+ | | U1B |
| | U1A [240µF]| | |
| | C1| | | |
GND>-+--------+------------------+---+-----+---------+


Do you need a circuit description?

C(harge)R(apidly)1 - clever! I would not have thought
of it.
 
F

Fred Bloggs

Jan 1, 1970
0
Mike said:
Hi,
Does anyone have a schematic, kit, or a complete product to sense a line
level audio signal and turn a remote power amplifier on? I have done all the
searches I can think of and have not found anything. These things can't be
that rare!!
Thanks...Mike DeAngelis

The audio line activated switch is not VOX as some have claimed- VOX is
largely a radio term and describes detecting a few tens of mV or less of
microphone output. Your circuit is working off of 100mV,RMS minimum, and
up to 2V,RMS, into 10K loading. All you need to do is gain that up,
rectify, smooth, and drive a relay. Actually, you don't need to do any
of that using a single transistor and a CMOS 555. The circuit below uses
a 2N3904 to gain up the line input to a 5Vpp swing at the 555 TRIG
input. As long as the 555 receives triggers before the 15u can
discharge, which takes about 2 mins, it will remain on keeping the relay
activated. No adjustment should be necessary.
View in a fixed-width font such as Courier.

..
..
..
.. NEUT ------------->
.. GND -+----------->
.. |
.. .-----------'
.. |
.. (-)---------+ HOT -----o---v
.. 5V | o--->
.. (+)---------|---------.
.. |100u + | |
.. +--||-----+
.. \ | | |
.. \|--+--||-----+
.. \| 0.1U | |
.. | --------
.. .-----+----+------+---------+---|/ / / / |-.
.. AUDIO | | | | | -------- |
.. LINE 0.022u | | +| | +------|<|-----+
.. IN>--+-||--. | | === [120K] | 1N4001 |
.. | | [100K] [10M] 15U | | |
.. | | | | | | TLC555------. |
.. | [10K] | | | | | VCC/RST | 2N4401 |
.. | | | | | | | | |/
.. | +-[4.7M]-+-|<|-+----+----------|THRESH OUT|-[1K]-|
.. | | |1N4148 | | | | |>
.. | | 22p | | | | | |
.. | +---||---+-----------------|---|TRIG DIS|--. |
.. | | | | | | | | |
.. | | | | | | | | |
.. | | |/ | +---|CONT | | |
.. | '------|2N3904 | | | | | |
.. | |> | | | GND | | |
.. | | | | '-----------' | |
.. [1M] | | | | | |
.. | | | [100K] | | |
.. | | | | | | |
.. | | | | | | |
.. | | | | | | |
.. '--------------+-----------------+-----------+------|-----'
.. | | |
.. --- | |
.. /// '-------------------------'
..
 
F

Fred Bloggs

Jan 1, 1970
0
Mike said:
Hi,
Does anyone have a schematic, kit, or a complete product to sense a line
level audio signal and turn a remote power amplifier on? I have done all the
searches I can think of and have not found anything. These things can't be
that rare!!
Thanks...Mike DeAngelis

6V RMS is not LINE level audio, but it makes no difference- just use a
reverse diode in shunt with the input transistor base:
View in a fixed-width font such as Courier.

..
..
..
.. NEUT ------------->
.. GND -+----------->
.. |
.. .-----------'
.. |
.. (-)---------+ HOT -----o---v
.. 5V | o--->
.. (+)---------|---------.
.. |100u + | |
.. +--||-----+
.. \ | | |
.. \|--+--||-----+
.. \| 0.1U | |
.. | --------
.. .-----+----+------+---------+---|/ / / / |-.
.. AUDIO | | | | | -------- |
.. LINE 0.022u | | +| | +------|<|-----+
.. IN>--+-||--. | | === [120K] | 1N4001 |
.. | | [100K] [10M] 15U | | |
.. | | | | | | TLC555------. |
.. | [10K] | | | | | VCC/RST | 2N4401 |
.. | | | | | | | | |/
.. | +-[4.7M]-+-|<|-+----+----------|THRESH OUT|-[1K]-|
.. | | |1N4148 | | | | |>
.. | | 22p | | | | | |
.. | +---||---+-----------------|---|TRIG DIS|--. |
.. | | | | | | | | |
.. | | | | | | | | |
.. | | |/ | +---|CONT | | |
.. | +------|2N3904 | | | | | |
.. | | |> | | | GND | | |
.. | | | | | '-----------' | |
.. [1M] | 1N4148 | | | | | |
.. | '--|<|---+ | [100K] | | |
.. | | | | | | |
.. | | | | | | |
.. | | | | | | |
.. '--------------+-----------------+-----------+------|-----'
.. | | |
.. --- | |
.. /// '-------------------------'
..
 
M

Mike DeAngelis

Jan 1, 1970
0
Sorry, I should have said 6 v p-p. That is the stated output of a networked
music player that will be driving this amplifier.
...Mike

Fred Bloggs said:
Mike said:
Hi,
Does anyone have a schematic, kit, or a complete product to sense a line
level audio signal and turn a remote power amplifier on? I have done all the
searches I can think of and have not found anything. These things can't be
that rare!!
Thanks...Mike DeAngelis

6V RMS is not LINE level audio, but it makes no difference- just use a
reverse diode in shunt with the input transistor base:
View in a fixed-width font such as Courier.

.
.
.
. NEUT ------------->
. GND -+----------->
. |
. .-----------'
. |
. (-)---------+ HOT -----o---v
. 5V | o--->
. (+)---------|---------.
. |100u + | |
. +--||-----+
. \ | | |
. \|--+--||-----+
. \| 0.1U | |
. | --------
. .-----+----+------+---------+---|/ / / / |-.
. AUDIO | | | | | -------- |
. LINE 0.022u | | +| | +------|<|-----+
. IN>--+-||--. | | === [120K] | 1N4001 |
. | | [100K] [10M] 15U | | |
. | | | | | | TLC555------. |
. | [10K] | | | | | VCC/RST | 2N4401 |
. | | | | | | | | |/
. | +-[4.7M]-+-|<|-+----+----------|THRESH OUT|-[1K]-|
. | | |1N4148 | | | | |>
. | | 22p | | | | | |
. | +---||---+-----------------|---|TRIG DIS|--. |
. | | | | | | | | |
. | | | | | | | | |
. | | |/ | +---|CONT | | |
. | +------|2N3904 | | | | | |
. | | |> | | | GND | | |
. | | | | | '-----------' | |
. [1M] | 1N4148 | | | | | |
. | '--|<|---+ | [100K] | | |
. | | | | | | |
. | | | | | | |
. | | | | | | |
. '--------------+-----------------+-----------+------|-----'
. | | |
. --- | |
. /// '-------------------------'
.
 
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