Driver to drive?

[Joel Kolstad]

"Don Klipstein" <don@manx.misty.com> wrote in message
news:slrncog9j4.hsp.don@manx.misty.com...

The ballast voltage and the lamp voltage are not in phase with each
other, so the magnitudes of the individual voltages add up to more than
120V.

I'll accept that. Is there a commonly accepted equivalent circuit model for
a fluorescent bulb? Better than my 'single resistor' model?

Thanks for the additional information. I was trying to provide the order of
magnitude of the answer, and I'm glad you could provide a more detailed
answer.

I believe these are made by low bid manufacturers, and have as much
nonlinearity, saturation, and resistive losses as they can get away with.
I would guess they are reasonably linear for currents from a couple 10's
of mA to instantaneous current of about 350 mA, but not an especially high
Q
at any frequency.

It's rather ironic that one of the best selling features of fluorescent
bulbs -- high efficiency -- is degraded due to the drive for a slightly
smaller selling price.

---Joel

 

[Kevin Aylward]

Fred Bartoli wrote:

"Kevin Aylward" <salesEXTRACT@anasoft.co.uk> a écrit dans le message
de newsVFid.22885$Fu2.18127@fe1.news.blueyonder.co.uk...

Indeed. How about looking at spice model data

Typically jfets are set to Vtotc=-2.5m (Vto temp co) and
Betatce=-500m (transconductance exponential temp co). i.e. ID =
Beta.(Vgs-Vto)^2

Note: Beta = Beta_0 x 1.01 x exp(Betatce.(T-Tnom)). This is the
PSpice formula, and implemented in SS, but probably not implemented
in most other spices other than LTSpice. However, the last time I
checked LTSpice did not implement this PSpice specific temp co for
gasfets/mesfets, unlike SS


Do you know where does the 1.01 factor come from ?

Yes. The Dos PSpice, Jan 1989 manual

Oh, and I meant 1.01 ^ (Betatce.(T-Tnom)).

Not the exponential function. I as not very clear on this. Obviously,
for T=tnom, we need a unity multiplier.

Kevin Aylward
salesEXTRACT@anasoft.co.uk
http://www.anasoft.co.uk
SuperSpice, a very affordable Mixed-Mode
Windows Simulator with Schematic Capture,
Waveform Display, FFT's and Filter Design.

 

[Paul Burke]

jean@vaneskahian.com (Jean-Marie Vaneskahian) wrote:


I Need To Trigger a Relay When an LED Lights Up On a Smoke Detector

My goal is to use simple battery operated combination Smoke / Carbon
Monoxide detectors in various parts of my house. I want these battery
operated detectors to trigger a simple contact closure when they
alarm.

I noticed that the detectors have a Red LED that lights up when the
Smoke / Carbon Monoxide detector is triggered. I soldered two small
wires to the PCB on the back of the detector in "parallel" with the
Red LED.

When I connect a voltmeter to the two wires I soldered in "parallel"
with the Red LED and now run from the back of the PCB of the Smoke /
Carbon Monoxide detector I get about +0.001V when nothing happens and
+1.78V when I hit the test button on the Smoke / Carbon Monoxide
detector. By the way, the Smoke / Carbon Monoxide detector runs on a
total of 3 AAA 1.5V batteries.

I have a very basic electronics understanding. One concept that I do
NOT understand is that of "Ground". I do understand how to "Wire"
components though.

My question is this:

How do I take the 2 wires running from the back of the PCB on the
Smoke / Carbon Monoxide detector and generate a basic dry "Contact
Closure" when the detector is triggered?

I am sure this requires transistors, diodes, resistors, reed switches
and a separate battery source, but I have no clue how to connect them
and what types and values to purchase. I buy most of these components

from Radio Shack (Part Numbers Would Be Great!).

Please help me put this together. I really appreciate any wisdom on
this topic. My goal is to protect my family by wiring these battery
operated Smoke / Carbon Monoxide detectors to my home alarm system
that uses contact closures.

You best bet, which would not invalidate any warranties such as they are
worth, and more to the point wouldn't get you burned alive if there is a
fire and the alarm doesn't go off, is to put a photodiode sensor near
the existing LED and trigger the relay off that. Radio Snack, Maplin or
whatever will probably have a project kit for this that you could modify
to suit.

Paul Burke

 

[Rich Grise]

On Wed, 03 Nov 2004 04:25:05 +0000, Leon Heller wrote:

"Dummy" <ahkit1021@yahoo.com> wrote in message
news:74bb84c0.0411021808.24369694@posting.google.com...
There are two VHF (136-174MHz) radios and two UHF (438-470MHz) radios.
For UHF radios, some kind of noise appeared at receiver radio's
speaker when key chain is jingled at the transmitting radio. This
happened even when the microphone was disabled/unplugged from the
transmitting radio. I don't see any way that the noise could be
coupled to the microphone. The noise amplitude (as audible) was much
more lower when antenna was detached. What actually happened there? No
such peculiar phenomena was been observed in VHF radios though. I
suppose it's the interaction between the key chain and RF radiation
field, and caused VCO pulling?

Perhaps there is a microphonic capacitor in the Tx. Many ceramic capacitors
are microphonic.

I'd be more likely to think it's actually the keys in the RF field.

I seriously doubt if a microphonic capacitor would act like an acoustic
microphone with the kind of sensitivity that you'd need to pick up
the jingling of keys. If that were the case, you wouldn't be able to
carry on a conversation in the room. And I've seen a very sensitive
UHF receiver that would trigger on jingled keys without even a
transmitter nearby, albeit there were transmitters in the vicinity -
it was USAF tech. school.

Cheers!
Rich

 

[Keith Williams]

In article <u8pvo0lag6docip2nji2on0arm6reirnro@4ax.com>,
l_o_u_s_take_most_away@xs4all.nl says...

shoppa@trailing-edge.com (Tim Shoppa) wrote:

program2gether@hotmail.com (nick) wrote in message news:<bb338404.0411050543.bfa3f6c@posting.google.com>...
8 variables are just inputs,my circuit has 8 inputs,and 9 outputs.

256x9 PROM.

Tim.
Right. When I was a student I had an small PC-XT with only 512K Ram.
What I wanted was to add some memory, which was not supported by the
circuit board. The memory was addressed via a PAL of unknown
contents. Inputs=9, outputs=8.

No PAL at all.

What I did was wire it to a socket with a 2764 EPROM layout and read
it as if it was an Eprom.

Too much work. The 5160 (PC/XT) supported 640K on the motherboard.
All that was needed was replace two banks of 64Kx1 DRAMs with 256Kx1
DRAMs add a 74LS139 (IIRC) and a jumper. ...all done.


--
Keith

 

[Fred Bloggs]

Jean-Marie Vaneskahian wrote:

I Need To Trigger a Relay When an LED Lights Up On a Smoke Detector

My goal is to use simple battery operated combination Smoke / Carbon
Monoxide detectors in various parts of my house. I want these battery
operated detectors to trigger a simple contact closure when they
alarm.

I noticed that the detectors have a Red LED that lights up when the
Smoke / Carbon Monoxide detector is triggered. I soldered two small
wires to the PCB on the back of the detector in "parallel" with the
Red LED.

When I connect a voltmeter to the two wires I soldered in "parallel"
with the Red LED and now run from the back of the PCB of the Smoke /
Carbon Monoxide detector I get about +0.001V when nothing happens and
+1.78V when I hit the test button on the Smoke / Carbon Monoxide
detector. By the way, the Smoke / Carbon Monoxide detector runs on a
total of 3 AAA 1.5V batteries.

I have a very basic electronics understanding. One concept that I do
NOT understand is that of "Ground". I do understand how to "Wire"
components though.

My question is this:

How do I take the 2 wires running from the back of the PCB on the
Smoke / Carbon Monoxide detector and generate a basic dry "Contact
Closure" when the detector is triggered?

I am sure this requires transistors, diodes, resistors, reed switches
and a separate battery source, but I have no clue how to connect them
and what types and values to purchase. I buy most of these components
from Radio Shack (Part Numbers Would Be Great!).


Thanks a million in advance,
Jean-Marie Vaneskahian
jean@vaneskahian.com

If all the detectors are battery powered and isolated, then you can
connect them all as shown below- embed the three components in each
detector as shown- tie all collectors to junction CJ and all emitters to
junction EJ and connect into relay driver as shown. You void *all*
warranties and assume *all* risk by modifying the existing products,
THIS IS STRICTLY A HOBBY CIRCUIT- you should have unmodified backup
parts working in parallel with ones you modify.

View in a fixed-width font such as Courier.


.
. RELAY DRIVER SMOKE
. +----------------+ +-----------------ALARM-------------------+
. | CJ | | \ |
. | +----LOAD---+--|----|------+ +-----o o-----+ |
. | | | | | | | | |
. | | | | | c | | |
. | | | | | \| 4.7K | | |
. | | | | | 2N4401|--/\/\-+------+ | |
. |--- relay | | | /| | | | |
. | - batt | | | e / --- --- |
. | | | | | | 10K \ / ~~~ - |
. | | | | | | / --- LED | |
. | | | | | | \ | Vf=1.8V | |
. | | EJ | | | | | | | |
. | +--------------|----|------+---------+------+--------------+ |
. | | | | | |
. | | | | | |
. |----------------+ +-----------------------------------------+
. | |
. | | SMOKE
. | | +----------------- ALARM------------------+
. | | | |
. | +-------|------+ +--------------+ |
. | | | | | | |
. | | | c | | |
. | | | \| 4.7K | | |
. | | | 2N4401|--/\/\-+------+ | |
. | | | /| | | | |
. | | | e / --- --- |
. | | | | 10K \ / ~~~ - |
. | | | | / --- LED | |
. | | | | \ | Vf=1.8V | |
. | | | | | | \ | |
. +-------------------|------+---------+------+-----o o-----+ |
. | | | |
. | | +-----------------------------------------+
. v v
. to
. other SA's
.
.
.
.
.
.
.
. RELAY DRIVER
. +------------------+----------+-----+
. | | | |
. | | | /
. | +---+ | 10K
. | | | | /
. | --- )||R e \
. | 1N4001/ \ )||E \| |
. | --- )||L 2N4403 |---+
. | | )||A /| |
. --- RELAY | | Y c /
. - BATT +---+ | 10K
. | | / /
. | | 1K \
. | | / |
. | c \ +----CJ
. | \| |
. | 2N4401 |--------+
. | /| |
. | e /
. | | 10K
. | | /
. | | \
. | | |
. +------------------+----------+----------EJ
.
.
.

 

[Robert Baer]

Spehro Pefhany wrote:

On 2 Nov 2004 10:46:32 -0800, the renowned
david.pariseau@sbcglobal.net (David Pariseau) wrote:

The problem was actually a voltage spike on startup (switching on the
Variac) that was large enough (>9000v) to toast the reference. I
guess it makes sense that the auto-transformer might have such an
excursion initially with such light load.

I added a 10K resistor in series with my 450K resistor and added a TVS
from this new node to ground and voila...

Thanks to all for your input.

Dave.

I would have thought the 3.3uF would have killed any such spikes. Do
you actually have that part installed?

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

Electrolytics are traditionally poor on HF bypass - which degrades
over time.

 

[Robert Baer]

Rich Grise wrote:

On Wed, 03 Nov 2004 00:02:14 +0000, Pooh Bear wrote:



Norm Dresner wrote:

Were the Current Regulating Diodes simply a good idea that never made it in
the marketplace?

I think they were a ruse to sell more FETs. ;-)


Since they're essentially a JFET at zero bias, they're probably that
expensive to characterize, or it could be just lack of demand.

Although, it might be interesting to measure a batch of jellybean JFETS
and see what you'd get.

Just short the gate to the source, and see what its current is.

Cheers!
Rich

Prolly a fair variation, but the "pinchoff" voltage has only a small
variation.
So, use of one 1% resistor to set the current, and making sure the
drop across the FET is larger than the pinchoff voltage, the result is a
constant current regulator good to a few percent in practice.
And using a DMOS FET, that current remains the same from pinchoff to
breakdown!

 

[Ratch]

"Fred Bloggs" <nospam@nospam.com> wrote in message
news:418B9C07.4020308@nospam.com...

Ratch wrote:
[..snip..]
YOU'RE A FUCKING LIAR!!!!

Everything I told you was the truth as I see it. Lying has to have
intent.

You live in Minnesota-

Yes, land of blond hair and blue ears.

there is no way in hell
you are seeing the ostentatious behavior you claim to see.

Once in a while we do, but there is the mass media that brings it home
it us also.

\You are A
GODDAMED RELIGIOUS RIGHT NUTCASE WHO HAS BEEN SUCKERED INTO BUYING A LOT
OF JERRY FALWELL VIDEOS!-

Nope, never purchased anything from Fartwell.

that is exactly what you are- a goddammed
deceitful religious right shithead. Here's the deal, scumbag- you people
made a BIG BIG BIG mistake electing Bush- you will now be CRUSHED!

We liked a lot of the things he did before, and we think he will be
less prone to mistakes in the future. I cannot imagine having anyone else
who was available to lead us the last four years.

Time for your meds, before you pop a seal. Ratch
>

 

[John Larkin]

On Tue, 09 Nov 2004 04:15:31 GMT, "Ratch" <Watchit@Comcast.net> wrote:

And isn't it a valid question to ask whether taking out an asshole of
his magnitude justifies taking out tens of thousands of civilians,

Yes, it is and the answer is yes. How many civilians did Saddam kill
within his own country and the war with Iran?

Estimated 2e6.

John

 

[Andrzej Kamieniecki]

Uzytkownik "Klaus Kragelund" <klauskvik@hotmail.com> napisal w wiadomosci
news:881355e2.0411010609.578f67cc@posting.google.com...

30VRMS with a standard P2220 probe

yes, but only for x1 attenuation (see user manual 071-1441-00, page F-1)

How is the isolation done inside the scope? Its quite cheap, around
5k$ with 4 probes and with nice 200MHz bandwidth performance.....

In TPS series each channel consist with:
- two mixers AD8343 DC-2,5GHz (Analog Devices)
- one isolation transformer PT77172 (Datatronics)
- two differential drivers AD8131 (Analog)
and also several other parts.
Basic idea is modulation on both site of transformer.

Andrzej Kamieniecki

 

[Clarence]

"ChrisGibboGibson" <chrisgibbogibson@aol.com> wrote in message
news:20041108195153.07103.00000275@mb-m10.aol.com...

It may be sheer coincidence (in fact it probably is) but in the UK Raleigh
(sp?) used to sell a range of products called the RSW range. It was a girl's
bike.

Gibbo

Does Raleigh still build the "Abby?"

 

[Frithiof Andreas Jensen]

"feilip" <feilip@gmail.com> wrote in message
news:9c0f797a.0411011121.47e79c16@posting.google.com...

I just wonder what is a typical design steps if I use a transmitter
chip, such as, Texas Instruments TRF6900, to build a transmitter.

1) Work out what you want to do. (A mission Statement).

2) Work out what you *need*, in function blocks, in order to do what you
want to do . (Requirements Gathering).

3) Find out if there is something in the market that (mostly) does this.
(Search for an existing solution).

....This is where you are now, rite?

4) Find out who the supplier is and especially if you can actually *obtain*
the device *now*. (Debunk blatant vendor Lies).

5) Get the data-sheet, any application notes, errata etc. on the device.
Especially take note of any warnings in the application notes that the
designers managed to slip past Sales and Marketing such as recommended
layout and power supply decoupling; if it's there, somebody stuck their neck
out for you and they really mean it. (Gather design information).

6) Build the circuit closest to your application from the application note -
or get an evaluation board if it is available. (Design, Debunk more lies).

7) Work out what is wrong with the application circuit. (Test, debunk yet
more lies).

8) Then add the missing functionality and fix the broken features. (Debug,
Test, Design, Verify).

8a) Then find out that the device is now on Last Order By ... status ;-{
8b) You are actually done.

simulate the chip with external passive components in some software
such as Agilent ADS?

Easier to get the application board, if any, or just build the device
outright. Simulation of complex mixed analog/digital devices is often hairy
and difficult to verify properly anyway - often it is faster just to build
the prototype and measure on the real thing.

 

[Frithiof Andreas Jensen]

"Fred Bloggs" <nospam@nospam.com> skrev i en meddelelse
news:418D5DA1.1010609@nospam.com...

Apparently this is still practiced:

"However, a small number of Orthodox rabbis advocate an ancient practice
in which the circumciser sucks

And I thought the Catholic Church had problems ;-))

 

[Frank Bemelman]

"John Larkin" <jjlarkin@highSNIPlandTHIStechPLEASEnology.com> schreef in
bericht news:9n12p019237l6gvgfnkmtf5tobhfmefed1@4ax.com...

On Tue, 09 Nov 2004 04:15:31 GMT, "Ratch" <Watchit@Comcast.net> wrote:


And isn't it a valid question to ask whether taking out an asshole of
his magnitude justifies taking out tens of thousands of civilians,

Yes, it is and the answer is yes. How many civilians did Saddam kill
within his own country and the war with Iran?


Estimated 2e6.

snippet from:
http://www.globalpolicy.org/security/issues/iraq/attack/consequences/2004/1029deathtoll.htm

------
The Lancet, a respected British medical journal, reports that the US and
coalition forces (but mainly the US Air Force) has killed 100,000 Iraqi
civilians since the fall of Saddam on April 9, 2003. Previous estimates for
civilian deaths since the beginning of the war ranged up to 16,000, with the
number of Iraqi troops killed during the war itself put at about 6,000.

The troubling thing about these results is that they suggest that the US may
soon catch up with Saddam Hussein in the number of civilians killed. How
many deaths to blame on Saddam is controverial. He did after all start both
the Iran-Iraq War and the Gulf War. But he also started suing for peace in
the Iran-Iraq war after only a couple of years, and it was Khomeini who
dragged the war out until 1988. But if we exclude deaths of soldiers, it is
often alleged that Saddam killed 300,000 civilians. This allegation seems
increasingly suspect. So far only 5000 or so persons have been found in mass
graves. But if Roberts and Burnham are right, the US has already killed a
third as many Iraqi civilians in 18 months as Saddam killed in 24 years.
------


--
Thanks, Frank.
(remove 'x' and 'invalid' when replying by email)

 

[Terry Given]

Frank Bemelman wrote:

"Spehro Pefhany" <speffSNIP@interlogDOTyou.knowwhat> schreef in bericht
news:md72p0pqet254mchv2r194jda7llpajqgh@4ax.com...

On Tue, 09 Nov 2004 10:06:44 -0800, the renowned John Larkin
jjlarkin@highSNIPlandTHIStechPLEASEnology.com> wrote:


On Tue, 09 Nov 2004 04:15:31 GMT, "Ratch" <Watchit@Comcast.net> wrote:


And isn't it a valid question to ask whether taking out an asshole of
his magnitude justifies taking out tens of thousands of civilians,

Yes, it is and the answer is yes. How many civilians did Saddam kill
within his own country and the war with Iran?


Estimated 2e6.

John

Any pre-9/11 cites for that estimate?


If this were a quiz, I'd guess 1e5 comes closer.

Hey, lets not forget the 0.5e6 Iraqi children (mostly) that died during
the sanctions, which prevented Iraq from buying medicine or medicinal
equipment. You know, the 500,000 people Madelain Allbright said were
"acceptable" to let die.

I could never understand why the sanctions included medical supplies,
until I started thinking about the effect. IMO the real reason was to
maximise the anger of the Iraqi people, in the hope they would tolerate
the nut that had all the guns. didnt work, but whacked a lotta kids. not
good. Why couldnt they just drop a half-dozen 500lb bombs on each of the
bastards palaces.

Cheers
Terry

 

[legg]

On 1 Nov 2004 06:09:38 -0800, klauskvik@hotmail.com (Klaus Kragelund)
wrote:

Hi

Tektronix has recently launched a new TPS2000 series cheap scopes that
provide isolation between the inputs and ground by default:

http://www.tek.com/site/ps/0,,3M-17750-INTRO_EN,00.html?wt=510&link=/site/ps/0,,3M-17750-INTRO_EN,00.html

Does anyone know how they acchieve the 600VRMS isolation with the aid
of the P5120 passive probe? (30VRMS with a standard P2220 probe)

How is the isolation done inside the scope? Its quite cheap, around
5k$ with 4 probes and with nice 200MHz bandwidth performance.....

Pity they can't improve rejection ratios between channels.

Even isolated, looking at large and small signals simultaneously is
prone to this error, and you basically 'don't do that', as a solution.

I wonder if the recal of TDS series products (ground discontinuity due
to user abuse/error - supposedly 'unsafe') was a ploy to flog the new
stuff?

RL

 

[Ken Taylor]

"Frithiof Andreas Jensen" <frithiof.jensen@diespammerdie.jensen.tdcadsl.dk>
wrote in message news:41911d83$0$201$edfadb0f@dread11.news.tele.dk...

"Fred Bloggs" <nospam@nospam.com> skrev i en meddelelse
news:418D5DA1.1010609@nospam.com...
Apparently this is still practiced:

"However, a small number of Orthodox rabbis advocate an ancient practice
in which the circumciser sucks

And I thought the Catholic Church had problems ;-))


It does, but Fred has an even bigger one.