A real quickie
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Posts: 46,084
What about a resistor divider ? It is the simplest but not isolated.
AC Jacques
Chris Loiacono wrote:
>
> Help!
>
> Can someone show me how to get a 120V 60Hz line down to 10V 60Hz or less
> with few components?
> I want to use the line frequency on a stamp input. Actually, 10VAC would be
> perfect.
>
> C'mon - someone's gotta be able to figure this out with your eyes closed....
AC Jacques
Chris Loiacono wrote:
>
> Help!
>
> Can someone show me how to get a 120V 60Hz line down to 10V 60Hz or less
> with few components?
> I want to use the line frequency on a stamp input. Actually, 10VAC would be
> perfect.
>
> C'mon - someone's gotta be able to figure this out with your eyes closed....
Comments
chris01@t... writes:
> Can someone show me how to get a 120V 60Hz line down to 10V 60Hz or less
> with few components? I want to use the line frequency on a stamp input.
> Actually, 10VAC would be perfect.
>
> C'mon - someone's gotta be able to figure this out with your eyes closed....
How about a small transformer and a half-wave rectifer (diode, i.e., 1N4001)?
Tim
[noparse][[/noparse]Denver, CO]
> Help!
>
> Can someone show me how to get a 120V 60Hz line down to 10V
> 60Hz or less
> with few components?
> I want to use the line frequency on a stamp input. Actually,
> 10VAC would be
> perfect.
>
> C'mon - someone's gotta be able to figure this out with your
> eyes closed....
Can someone show me how to get a 120V 60Hz line down to 10V 60Hz or less
with few components?
I want to use the line frequency on a stamp input. Actually, 10VAC would be
perfect.
C'mon - someone's gotta be able to figure this out with your eyes closed....
I forgot to say - no inductors - The circuit I'm controlling requires that
there's no phase shift....
Original Message
From: jonwms@a... [noparse]/noparse]mailto:[url=http://forums.parallaxinc.com/group/basicstamps/post?postID=yE_hO8AxwP5Nl29D-WQ5tjBcNstlw-4akq7OPKhcpPG8yMDymlC3XVUi3JJT-OwnHdMNvJXuIg]jonwms@a...[/url
Sent: Tuesday, October 17, 2000 10:19 AM
To: basicstamps@egroups.com
Subject: Re: [noparse][[/noparse]basicstamps] A real quickie
In a message dated 10/17/00 10:14:45 AM Central Daylight Time,
chris01@t... writes:
> Can someone show me how to get a 120V 60Hz line down to 10V 60Hz or less
> with few components? I want to use the line frequency on a stamp input.
> Actually, 10VAC would be perfect.
>
> C'mon - someone's gotta be able to figure this out with your eyes
closed....
How about a small transformer and a half-wave rectifer (diode, i.e.,
1N4001)?
divider?
if you're only using it for timing you an use large resistor values..
Jason
Chris Loiacono wrote:
> Thanks, but...
> I forgot to say - no inductors - The circuit I'm controlling requires that
> there's no phase shift....
>
>
Original Message
> From: jonwms@a... [noparse]/noparse]mailto:[url=http://forums.parallaxinc.com/group/basicstamps/post?postID=FQQ_oPrpVqA29f_PKdqXt7YHz4C3fv9JQUyjUhIwKo9OJXEaeS3VGQVKnqor7cAfUgCRPIgg]jonwms@a...[/url
> Sent: Tuesday, October 17, 2000 10:19 AM
> To: basicstamps@egroups.com
> Subject: Re: [noparse][[/noparse]basicstamps] A real quickie
>
> In a message dated 10/17/00 10:14:45 AM Central Daylight Time,
> chris01@t... writes:
>
> > Can someone show me how to get a 120V 60Hz line down to 10V 60Hz or less
> > with few components? I want to use the line frequency on a stamp input.
> > Actually, 10VAC would be perfect.
> >
> > C'mon - someone's gotta be able to figure this out with your eyes
> closed....
>
> How about a small transformer and a half-wave rectifer (diode, i.e.,
> 1N4001)?
A resistor divider is ok, but use it to power an opto-isolator instead of
directly to a Stamp pin...
100K 2.2K
120V AC >----/\/\--o---/\/\---o----< 120V AC
| 1N4001 |
o----|<----o
| OPTO-LED |
o---->|----o
//
E (OPTO-NPN) C---< +10V (from Supply) ...See Note:
|
o--/\/\
< GND
| 4.7K
o
> Output (60Hz 10V DC)
Note:
Use a +5V supply if you are connecting the Output (above) directly
to an I/O pin.
>ok, then how about a diode bridge (or half bridge) followed by a resistor
>divider?
>if you're only using it for timing you an use large resistor values..
>
>Jason
>
>Chris Loiacono wrote:
>
> > Thanks, but...
> > I forgot to say - no inductors - The circuit I'm controlling requires that
> > there's no phase shift....
> >
> >
Original Message
> > From: jonwms@a... [noparse]/noparse]mailto:[url=http://forums.parallaxinc.com/group/basicstamps/post?postID=l1oNwSpIf2do7dkNAE3PyCyJDkPncC0IJMtDvBBYfn61Ivtced8pJ1jSYqCZ6QNohMbsItKg]jonwms@a...[/url
> > Sent: Tuesday, October 17, 2000 10:19 AM
> > To: basicstamps@egroups.com
> > Subject: Re: [noparse][[/noparse]basicstamps] A real quickie
> >
> > In a message dated 10/17/00 10:14:45 AM Central Daylight Time,
> > chris01@t... writes:
> >
> > > Can someone show me how to get a 120V 60Hz line down to 10V 60Hz or less
> > > with few components? I want to use the line frequency on a stamp input.
> > > Actually, 10VAC would be perfect.
> > >
> > > C'mon - someone's gotta be able to figure this out with your eyes
> > closed....
> >
> > How about a small transformer and a half-wave rectifer (diode, i.e.,
> > 1N4001)?
Beau Schwabe IC Mask Designer
National Semiconductor Network Products Division
500 Pinnacle Court, Suite 525 Mail Stop GA1 Norcross, GA 30071
Beau is right...you must isolate from the line to prevent shocks and smoke.
His optocoupler looks good. A cheap Radio Shack transformer could also be
used. If the transformer has a constant load, the phase shift is fixed and
could be corrected in software.
Ray McArthur
With cap this optocoupler could be a sensor to detect 120V in another project
In theese to ways you got insulation.
I got a nice 8V chopped AC wave, then tried to input it into a pair of
comparators (339's), one inverted. The outputs in series should send a pulse
at the zero cross. For some unknown reason, when I tie the AC into the
inputs, it's as if they are being sinked away. I tried making current at
different tolerable amounts, but to no avail.
I'll try the opto circuit next. Does the transistor output provide an analog
signal, or am I missing something?
Chris
Original Message
From: Ray McArthur [noparse]/noparse]mailto:[url=http://forums.parallaxinc.com/group/basicstamps/post?postID=KN_TojkJVsS7dvthJ9h4AefkEPF_9J_rHNUUAdUc3XQbWaL3YvcrYUiFYnnXTBCj1IT5J1dUjhThxSA13nNr]rjmca@u...[/url
Sent: Tuesday, October 17, 2000 4:55 PM
To: basicstamps@egroups.com
Subject: Re: [noparse][[/noparse]basicstamps] A real quickie
Chris:
Beau is right...you must isolate from the line to prevent shocks and smoke.
His optocoupler looks good. A cheap Radio Shack transformer could also be
used. If the transformer has a constant load, the phase shift is fixed and
could be corrected in software.
Ray McArthur
>Well, it's back to the board for me anyway......
>I got a nice 8V chopped AC wave, then tried to input it into a pair of
>comparators (339's), one inverted. The outputs in series should send a pulse
>at the zero cross. For some unknown reason, when I tie the AC into the
>inputs, it's as if they are being sinked away. I tried making current at
>different tolerable amounts, but to no avail.
>
>I'll try the opto circuit next. Does the transistor output provide an analog
>signal, or am I missing something?
>
>Chris
>
>
Original Message
>From: Ray McArthur [noparse]/noparse]mailto:[url=http://forums.parallaxinc.com/group/basicstamps/post?postID=nuRyVHKQF_tXpY9BJ_kQxLNwLX3uMBphLJz9_xlgV00zgCPO4bq6OJ_MO8QfcnvbrcVPs7DpJSl2Hw]rjmca@u...[/url
>Sent: Tuesday, October 17, 2000 4:55 PM
>To: basicstamps@egroups.com
>Subject: Re: [noparse][[/noparse]basicstamps] A real quickie
>
>
>Chris:
>Beau is right...you must isolate from the line to prevent shocks and smoke.
>His optocoupler looks good. A cheap Radio Shack transformer could also be
>used. If the transformer has a constant load, the phase shift is fixed and
>could be corrected in software.
>
>Ray McArthur
Ahh, see, now it makes sense why you didn't want the phase to be out of
phase. [noparse]:o[/noparse])
Without isolation, the AC act's like an antenna towards the 339's -- Not
Good. [noparse]:o[/noparse](
If you use two OPTO-Couplers (PS2502-2 from Digi-Key -- I think is a Dual?)
and a few resistors (four) you can do this with isolation and without using
339's
(2) OPTO-LED-1 (1)
o
|<
o
| |
47K | 4.7K | 47K
120V AC >----/\/\--o----/\/\----o--/\/\----< 120V AC
| |
| OPTO-LED-2 |
o
>|
o
(3) (4)
(5) (7) (6) (8)
GND >
o----o o----o---> Output (...goes High at ZERO)
|
| 4.7K
o--/\/\--> +5V
Note: (1),(2),(3), ... (8) Equals the pin number on the Dual OPTO-Isolator
(1) - Anode LED 1
(2) - Cathode LED 1
(3) - Anode LED 2
(4) - Cathode LED 2
(5) - Emitter Transistor 2
(6) - Collector Transistor 2
(7) - Emitter Transistor 1
(8) - Collector Transistor 1
Beau Schwabe IC Mask Designer
National Semiconductor Network Products Division
500 Pinnacle Court, Suite 525 Mail Stop GA1 Norcross, GA 30071
drawer, and believe it or not, was thinking similarly for a few brief
moments. Then for some reason, I got dumb again, and put them away. The dual
opto chip is perfect! just a handful of resistors & modest current too!
I consider myself in your debt Beau, Thanks
Chris
Original Message
From: Beau Schwabe [noparse]/noparse]mailto:[url=http://forums.parallaxinc.com/group/basicstamps/post?postID=0lGm8Xf_7ZpZzrL79MPB0Qm0NFhDP1wk8gdk_rvN1ReqQzVPrmSsxK_aumH9gQkWQjDtho_i9WpBLoHasP2QZA]bschwabe@a...[/url
Sent: Wednesday, October 18, 2000 5:39 PM
To: basicstamps@egroups.com
Subject: RE: [noparse][[/noparse]basicstamps] A real quickie
At 04:40 PM 10/18/00 -0500, you wrote:
>Well, it's back to the board for me anyway......
>I got a nice 8V chopped AC wave, then tried to input it into a pair of
>comparators (339's), one inverted. The outputs in series should send a
pulse
>at the zero cross. For some unknown reason, when I tie the AC into the
>inputs, it's as if they are being sinked away. I tried making current at
>different tolerable amounts, but to no avail.
>
>I'll try the opto circuit next. Does the transistor output provide an
analog
>signal, or am I missing something?
>
>Chris
>
>
Original Message
>From: Ray McArthur [noparse]/noparse]mailto:[url=http://forums.parallaxinc.com/group/basicstamps/post?postID=kWQkpeNUBl0e3D2v0fkiFuvFYt-IaTI2HdeBVl6ikOGN9E17xs5uK2QsrF-2hwaBypdmuudzx4FNAWWn_A]rjmca@u...[/url
>Sent: Tuesday, October 17, 2000 4:55 PM
>To: basicstamps@egroups.com
>Subject: Re: [noparse][[/noparse]basicstamps] A real quickie
>
>
>Chris:
>Beau is right...you must isolate from the line to prevent shocks and smoke.
>His optocoupler looks good. A cheap Radio Shack transformer could also be
>used. If the transformer has a constant load, the phase shift is fixed and
>could be corrected in software.
>
>Ray McArthur
Ahh, see, now it makes sense why you didn't want the phase to be out of
phase. [noparse]:o[/noparse])
Without isolation, the AC act's like an antenna towards the 339's -- Not
Good. [noparse]:o[/noparse](
If you use two OPTO-Couplers (PS2502-2 from Digi-Key -- I think is a Dual?)
and a few resistors (four) you can do this with isolation and without using
339's
(2) OPTO-LED-1 (1)
o
|<
o
| |
47K | 4.7K | 47K
120V AC >----/\/\--o----/\/\----o--/\/\----< 120V AC
| |
| OPTO-LED-2 |
o
>|
o
(3) (4)
(5) (7) (6) (8)
GND >
o----o o----o---> Output (...goes High at ZERO)
|
| 4.7K
o--/\/\--> +5V
Note: (1),(2),(3), ... (8) Equals the pin number on the Dual OPTO-Isolator
(1) - Anode LED 1
(2) - Cathode LED 1
(3) - Anode LED 2
(4) - Cathode LED 2
(5) - Emitter Transistor 2
(6) - Collector Transistor 2
(7) - Emitter Transistor 1
(8) - Collector Transistor 1
Beau Schwabe IC Mask Designer
National Semiconductor Network Products Division
500 Pinnacle Court, Suite 525 Mail Stop GA1 Norcross, GA 30071