Isolating bridge rectifier...

server · Jul 25, 2020

I want to use the short audio output from my iPad to generate a brief 5V pulse for an Arduino circuit. I am using an existing pre-amp to take the roughly 200mv pk-pk ac to about 8V pk-pk. I thought Iâd follow that with a simple 4-diode bridge rectifier. The pre-amp and the Arduino circuit have a common ground rail. So is the correct method to take each of the pre-amp outputs to the bridge via a capacitor? Using 0.1uF, this appears to work OK (with a 4.7V zener to keep the pulse under 5V). But it does look a bit strange, so Iâm wondering if thereâs a neater way please?

Terry

server · Jul 25, 2020

On Sat, 25 Jul 2020 15:03:08 -0700 (PDT), terrypingm@gmail.com wrote:

I want to use the short audio output from my iPad to generate a brief 5V pulse for an Arduino circuit. I am using an existing pre-amp to take the roughly 200mv pk-pk ac to about 8V pk-pk. I thought Id follow that with a simple 4-diode bridge rectifier. The pre-amp and the Arduino circuit have a common ground rail. So is the correct method to take each of the pre-amp outputs to the bridge via a capacitor? Using 0.1uF, this appears to work OK (with a 4.7V zener to keep the pulse under 5V). But it does look a bit strange, so Im wondering if theres a neater way please?

Terry

How about a 2-diode voltage doubler? Load that with the zener and a
discharge resistor.

--

John Larkin Highland Technology, Inc

Science teaches us to doubt.

Claude Bernard

sea moss · Jul 26, 2020

On Saturday, July 25, 2020 at 3:03:13 PM UTC-7, terry...@gmail.com wrote:

I want to use the short audio output from my iPad to generate a brief 5V pulse for an Arduino circuit. I am using an existing pre-amp to take the roughly 200mv pk-pk ac to about 8V pk-pk. I thought Iâd follow that with a simple 4-diode bridge rectifier. The pre-amp and the Arduino circuit have a common ground rail. So is the correct method to take each of the pre-amp outputs to the bridge via a capacitor? Using 0.1uF, this appears to work OK (with a 4.7V zener to keep the pulse under 5V). But it does look a bit strange, so Iâm wondering if thereâs a neater way please?

Terry

You should be fine using just one half of the AC signal (after the pre-amp).. A single diode feeding a cap. Add a bleeder resistor across the cap for the end of the pulse. And a series resistor into the zener so it won\'t get hot (you can use the zener directly if the pulse is short enough). I drew it in LTSpice:

Version 4
SHEET 1 904 680
WIRE 608 48 576 48
WIRE 704 48 608 48
WIRE 848 48 784 48
WIRE 880 48 848 48
WIRE 160 64 112 64
WIRE 336 64 160 64
WIRE 480 64 400 64
WIRE 576 64 576 48
WIRE 576 64 480 64
WIRE 880 96 880 48
WIRE 480 112 480 64
WIRE 576 112 576 64
WIRE 112 128 112 64
WIRE 112 240 112 208
WIRE 480 240 480 176
WIRE 480 240 112 240
WIRE 576 240 576 192
WIRE 576 240 480 240
WIRE 880 240 880 160
WIRE 880 240 576 240
WIRE 112 272 112 240
FLAG 112 272 0
FLAG 848 48 Vout
FLAG 160 64 Vin
FLAG 608 48 Vcap
SYMBOL voltage 112 112 R0
WINDOW 123 0 0 Left 0
WINDOW 39 0 0 Left 0
SYMATTR InstName V1
SYMATTR Value SINE(0 8 1k 0 0 0 100)
SYMBOL diode 336 80 R270
WINDOW 0 32 32 VTop 2
WINDOW 3 0 32 VBottom 2
SYMATTR InstName D1
SYMBOL cap 464 112 R0
SYMATTR InstName C1
SYMATTR Value 1Âµ
SYMBOL res 560 96 R0
SYMATTR InstName R1
SYMATTR Value 10k
SYMBOL res 800 32 R90
WINDOW 0 0 56 VBottom 2
WINDOW 3 32 56 VTop 2
SYMATTR InstName R2
SYMATTR Value 1k
SYMBOL zener 896 160 R180
WINDOW 0 24 64 Left 2
WINDOW 3 24 0 Left 2
SYMATTR InstName D2
SYMATTR Value 1N750
TEXT 288 376 Left 2 !.tran 1

Terry Pinnell · Jul 26, 2020

Thanks both, much appreciate the fast replies. I\'ll breadboard later
this afternoon but the sims look good.

https://www.dropbox.com/s/044rbfu11mqb9cn/VoltageDoubler-2Diodes.jpg?raw=1

https://www.dropbox.com/s/g1ihjdqpkw7clig/RectifierSingleDiode-2.jpg?raw=1

Digressing: it\'s probably decades since I used LT Spice rather than my
familiar CircuitMaker 2000. Just installed it to run sea moss\'s version.
To save me some reading, from the state shown in my screenshot how would
I quickly display say only Vout please?

If I decide to try switching to LTS for the few sims I do as a hobbyist,
can anyone narrow down almost one million hits for \'LT Spice tutorials\'
to a few recommendations that should get me up and running please?

====================

sea moss <danluster81@gmail.com> wrote:

On Saturday, July 25, 2020 at 3:03:13 PM UTC-7, terry...@gmail.com wrote:
I want to use the short audio output from my iPad to generate a brief 5V pulse for an Arduino circuit. I am using an existing pre-amp to take the roughly 200mv pk-pk ac to about 8V pk-pk. I thought Id follow that with a simple 4-diode bridge rectifier. The pre-amp and the Arduino circuit have a common ground rail. So is the correct method to take each of the pre-amp outputs to the bridge via a capacitor? Using 0.1uF, this appears to work OK (with a 4.7V zener to keep the pulse under 5V). But it does look a bit strange, so Im wondering if theres a neater way please?

Terry

You should be fine using just one half of the AC signal (after the pre-amp). A single diode feeding a cap. Add a bleeder resistor across the cap for the end of the pulse. And a series resistor into the zener so it won\'t get hot (you can use the zener directly if the pulse is short enough). I drew it in LTSpice:

Version 4
SHEET 1 904 680
WIRE 608 48 576 48
WIRE 704 48 608 48
WIRE 848 48 784 48
WIRE 880 48 848 48
WIRE 160 64 112 64
WIRE 336 64 160 64
WIRE 480 64 400 64
WIRE 576 64 576 48
WIRE 576 64 480 64
WIRE 880 96 880 48
WIRE 480 112 480 64
WIRE 576 112 576 64
WIRE 112 128 112 64
WIRE 112 240 112 208
WIRE 480 240 480 176
WIRE 480 240 112 240
WIRE 576 240 576 192
WIRE 576 240 480 240
WIRE 880 240 880 160
WIRE 880 240 576 240
WIRE 112 272 112 240
FLAG 112 272 0
FLAG 848 48 Vout
FLAG 160 64 Vin
FLAG 608 48 Vcap
SYMBOL voltage 112 112 R0
WINDOW 123 0 0 Left 0
WINDOW 39 0 0 Left 0
SYMATTR InstName V1
SYMATTR Value SINE(0 8 1k 0 0 0 100)
SYMBOL diode 336 80 R270
WINDOW 0 32 32 VTop 2
WINDOW 3 0 32 VBottom 2
SYMATTR InstName D1
SYMBOL cap 464 112 R0
SYMATTR InstName C1
SYMATTR Value 1µ
SYMBOL res 560 96 R0
SYMATTR InstName R1
SYMATTR Value 10k
SYMBOL res 800 32 R90
WINDOW 0 0 56 VBottom 2
WINDOW 3 32 56 VTop 2
SYMATTR InstName R2
SYMATTR Value 1k
SYMBOL zener 896 160 R180
WINDOW 0 24 64 Left 2
WINDOW 3 24 0 Left 2
SYMATTR InstName D2
SYMATTR Value 1N750
TEXT 288 376 Left 2 !.tran 1

server · Jul 26, 2020

On Sun, 26 Jul 2020 14:45:30 +0100, Terry Pinnell
<me@somewhere.invalid> wrote:

Thanks both, much appreciate the fast replies. I\'ll breadboard later
this afternoon but the sims look good.

https://www.dropbox.com/s/044rbfu11mqb9cn/VoltageDoubler-2Diodes.jpg?raw=1

Two comments: The input isn\'t grounded, and the output goes up but
doesn\'t go down.

--

John Larkin Highland Technology, Inc

Science teaches us to doubt.

Claude Bernard

sea moss · Jul 26, 2020

Digressing: it\'s probably decades since I used LT Spice rather than my
familiar CircuitMaker 2000. Just installed it to run sea moss\'s version.
To save me some reading, from the state shown in my screenshot how would
I quickly display say only Vout please?

If I decide to try switching to LTS for the few sims I do as a hobbyist,
can anyone narrow down almost one million hits for \'LT Spice tutorials\'
to a few recommendations that should get me up and running please?

===================
Once you run the sim, there is an icon at the top of the screen for \"pick visible traces\", you use that to select what you want to look at.

I don\'t know how much value there is in watching tutorials on circuit simulators, unless there\'s a fancy function that is weird to setup. Much better to just poke around, and google things you can\'t figure out. I will say, on LTSpice, the first time you try to place a voltage source it seems odd. There is an icon of an AND gate for \"add component\", click on that, and at the far right you will see \"voltage\".

I prefer Simetrix since I have been using it almost daily for years; I\'m fast at all the basic stuff. But, it\'s not free, so when I\'m home I switch to LTSpice.

Terry Pinnell · Jul 26, 2020

sea moss <danluster81@gmail.com> wrote:

Digressing: it\'s probably decades since I used LT Spice rather than my
familiar CircuitMaker 2000. Just installed it to run sea moss\'s version.
To save me some reading, from the state shown in my screenshot how would
I quickly display say only Vout please?

If I decide to try switching to LTS for the few sims I do as a hobbyist,
can anyone narrow down almost one million hits for \'LT Spice tutorials\'
to a few recommendations that should get me up and running please?

====================

Once you run the sim, there is an icon at the top of the screen for \"pick visible traces\", you use that to select what you want to look at.

I don\'t know how much value there is in watching tutorials on circuit simulators, unless there\'s a fancy function that is weird to setup. Much better to just poke around, and google things you can\'t figure out. I will say, on LTSpice, the first time you try to place a voltage source it seems odd. There is an icon of an AND gate for \"add component\", click on that, and at the far right you will see \"voltage\".

I prefer Simetrix since I have been using it almost daily for years; I\'m fast at all the basic stuff. But, it\'s not free, so when I\'m home I switch to LTSpice.

Thanks, learning by doing is indeed my preferred approach, although it
can often accelerated by the right tutorials or books.

Terry Pinnell · Jul 26, 2020

jlarkin@highlandsniptechnology.com wrote:

On Sun, 26 Jul 2020 14:45:30 +0100, Terry Pinnell
me@somewhere.invalid> wrote:

Thanks both, much appreciate the fast replies. I\'ll breadboard later
this afternoon but the sims look good.

https://www.dropbox.com/s/044rbfu11mqb9cn/VoltageDoubler-2Diodes.jpg?raw=1

Two comments: The input isn\'t grounded, and the output goes up but
doesn\'t go down.

Thanks, yes, forgot that. Here\'s the revision:
https://www.dropbox.com/s/nvmn6y1q6kt9oiw/VoltageDoubler-2Diodes-2.jpg?raw=1

As for the indefinite signal output, that\'s because I\'m not sure how to
configure the simulation settings in CM 2000 to show the sine abruptly
becoming zero amplitude!

I\'ll have a try at it with LT Spice soon, as sea moss\'s version did not
have that issue. I thought I might fix it by playing with line 3 below,
but it didn\'t see to change anything.

*Spice netlist for Circuit:
C:\\Users\\terry\\Dropbox\\Electronics\\CIRCUITS\\MY FINISHED
CIRCUITS\\Rectifiers\\VoltageDoubler-2Diodes.CKT
D4 0 R1_1 D1N750
V1 V1_1 0 DC 0 SIN(0 8 1k 0) AC 1 0
D1 V1_1 R1_2 DDIODE
D2 0 V1_1 DDIODE
C1 0 R1_2 10uF
C2 0 0 10uF
R1 R1_1 R1_2 1k
..SAVE R1_1 R1_2 V1_1 @d4[id] @v1[p] v1#branch @v1[z] @d1[p] @d1[id]
@d2[p]
..SAVE @d2[id] @c1[p] @c1 @c2[p] @c2 @r1[p] @r1

* Selected Circuit Analyses :
..OP
..TRAN 20u 5m 0 20u

* Models/Subcircuits Used:

*1N750 4.7V 500mW Si Zener pkgIODE0.4 A,K
..MODEL D1N750 D(IS=1E-11 RS=9.066 N=1.27 TT=5E-8 CJO=4.351E-10 VJ=0.75
+ M=0.33 BV=4.519 IBV=0.01 )

*DIODE Default diode PARAMeter values pkgIODE0.4 A,K
..MODEL DDIODE D()
..END

server · Jul 27, 2020

On Sun, 26 Jul 2020 22:47:55 +0100, Terry Pinnell
<me@somewhere.invalid> wrote:

jlarkin@highlandsniptechnology.com wrote:

On Sun, 26 Jul 2020 14:45:30 +0100, Terry Pinnell
me@somewhere.invalid> wrote:

Thanks both, much appreciate the fast replies. I\'ll breadboard later
this afternoon but the sims look good.

https://www.dropbox.com/s/044rbfu11mqb9cn/VoltageDoubler-2Diodes.jpg?raw=1

Two comments: The input isn\'t grounded, and the output goes up but
doesn\'t go down.

Thanks, yes, forgot that. Here\'s the revision:
https://www.dropbox.com/s/nvmn6y1q6kt9oiw/VoltageDoubler-2Diodes-2.jpg?raw=1

Try this maybe:

https://www.dropbox.com/s/ulh5zzme51c462b/Audio_Doubler.jpg?raw=1

As for the indefinite signal output, that\'s because I\'m not sure how to
configure the simulation settings in CM 2000 to show the sine abruptly
becoming zero amplitude!

Use LT Spice! It lets you add delay to a sine start, and specify a
number of cycles.

--

John Larkin Highland Technology, Inc

Science teaches us to doubt.

Claude Bernard

Terry Pinnell · Jul 27, 2020

jlarkin@highlandsniptechnology.com wrote:

On Sun, 26 Jul 2020 22:47:55 +0100, Terry Pinnell
me@somewhere.invalid> wrote:

jlarkin@highlandsniptechnology.com wrote:

On Sun, 26 Jul 2020 14:45:30 +0100, Terry Pinnell
me@somewhere.invalid> wrote:

Thanks both, much appreciate the fast replies. I\'ll breadboard later
this afternoon but the sims look good.

https://www.dropbox.com/s/044rbfu11mqb9cn/VoltageDoubler-2Diodes.jpg?raw=1

Two comments: The input isn\'t grounded, and the output goes up but
doesn\'t go down.

Thanks, yes, forgot that. Here\'s the revision:
https://www.dropbox.com/s/nvmn6y1q6kt9oiw/VoltageDoubler-2Diodes-2.jpg?raw=1

Try this maybe:

https://www.dropbox.com/s/ulh5zzme51c462b/Audio_Doubler.jpg?raw=1

====================

That sims fine thanks, after playing with C and R values for a while.

As for the indefinite signal output, that\'s because I\'m not sure how to
configure the simulation settings in CM 2000 to show the sine abruptly
becoming zero amplitude!

Use LT Spice! It lets you add delay to a sine start, and specify a
number of cycles.

Thanks, the latter feature allowed the output to return to zero, which
CM fails to accomplish. The output reached 4.7V V quickly (about 1ms),
albeit in two \'steps\'.

https://www.dropbox.com/s/nwkzhw4aqc94oml/Rectifier-JL-LT-1.jpg?raw=1

I suppose I\'ll get used to it but LTS\'s UI seems a bit rough in places.
For example, I had to remove redundant component text in my image editor
for the screenshot below, as it seems that cannot be done in LTS.

BTW, I was surprised the zener did not need a series resistor.

server · Jul 27, 2020

On Mon, 27 Jul 2020 16:18:20 +0100, Terry Pinnell
<me@somewhere.invalid> wrote:

jlarkin@highlandsniptechnology.com wrote:

On Sun, 26 Jul 2020 22:47:55 +0100, Terry Pinnell
me@somewhere.invalid> wrote:

jlarkin@highlandsniptechnology.com wrote:

On Sun, 26 Jul 2020 14:45:30 +0100, Terry Pinnell
me@somewhere.invalid> wrote:

Thanks both, much appreciate the fast replies. I\'ll breadboard later
this afternoon but the sims look good.

https://www.dropbox.com/s/044rbfu11mqb9cn/VoltageDoubler-2Diodes.jpg?raw=1

Two comments: The input isn\'t grounded, and the output goes up but
doesn\'t go down.

Thanks, yes, forgot that. Here\'s the revision:
https://www.dropbox.com/s/nvmn6y1q6kt9oiw/VoltageDoubler-2Diodes-2.jpg?raw=1

Try this maybe:

https://www.dropbox.com/s/ulh5zzme51c462b/Audio_Doubler.jpg?raw=1

====================

That sims fine thanks, after playing with C and R values for a while.

As for the indefinite signal output, that\'s because I\'m not sure how to
configure the simulation settings in CM 2000 to show the sine abruptly
becoming zero amplitude!

Use LT Spice! It lets you add delay to a sine start, and specify a
number of cycles.

Thanks, the latter feature allowed the output to return to zero, which
CM fails to accomplish. The output reached 4.7V V quickly (about 1ms),
albeit in two \'steps\'.

https://www.dropbox.com/s/nwkzhw4aqc94oml/Rectifier-JL-LT-1.jpg?raw=1

I suppose I\'ll get used to it but LTS\'s UI seems a bit rough in places.
For example, I had to remove redundant component text in my image editor
for the screenshot below, as it seems that cannot be done in LTS.

BTW, I was surprised the zener did not need a series resistor.

I wouldn\'t expect a little audio amp to output enough current to fry
the zener, but the first cap can be sized to limit the current too. 8
volts p-p doubled into a 5 volt zener, with two diode drops, won\'t
pump a lot of current either.

The caps don\'t need to be equal.

What diodes did you use? The default in LT seems to be a sort of 1N914
type.

--

John Larkin Highland Technology, Inc

Science teaches us to doubt.

Claude Bernard

server · Jul 27, 2020

I used the default and changed later to 1N914, the first entry in the list.

Isolating bridge rectifier...

server

Guest

server

Guest

sea moss

Guest

Terry Pinnell

Guest

server

Guest

sea moss

Guest

Terry Pinnell

Guest

Terry Pinnell

Guest

server

Guest

Terry Pinnell

Guest

server

Guest

server

Guest

Welcome to EDABoard.com

Sponsor

Online statistics

Forum statistics

Isolating bridge rectifier...

server

Guest

server

Guest

sea moss

Guest

Terry Pinnell

Guest

server

Guest

sea moss

Guest

Terry Pinnell

Guest

Terry Pinnell

Guest

server

Guest

Terry Pinnell

Guest

server

Guest

server

Guest

Log in

Welcome to EDABoard.com

Sponsor