COMPGROUPS.NET | Search | Post Question | Groups | Stream | About | Register

### Looking for low-side switch with crrent sensing

• Email
• Follow

I need to make a heater circuit more intelligent.  The existing design uses
a low-side switch with with a simple logic feedback to check for proper
operation.  An objective is to replace that with a device that will provide
a voltage output proportional to the heater current.

I have found a few high-side switches that will do the job and I am starting
to lean that way.


 0
Reply rphenry (125) 3/14/2005 3:07:28 PM

See related articles to this posting

On Mon, 14 Mar 2005 08:21:39 -0800, Luhan Monat wrote:
> Richard Henry wrote:
>
>> I need to make a heater circuit more intelligent.
>
> Ok, but to do exactly what?

To monitor the current going to the heater, as he says below.

>   The existing design uses
>> a low-side switch with with a simple logic feedback to check for proper
>> operation.
>
> Some safety feature, perchance?

Does it matter in the context of the question?

>    An objective is to replace that with a device that will provide
>> a voltage output proportional to the heater current.
>>
>
> Not proportional to temperature?  Just why do you need to know the current?

Can you truly not think of any good reasons for wanting to monitor
the heater current?  Ah well chalk it up to either a lack of imagination
or a lack of experience.  How is the reason he wants to monitor the
current relevant to the question?

>> I have found a few high-side switches that will do the job and I am starting
>> to lean that way.
>>
>
> Don't mean to be rude here, but this is a great example of 'how not to
> ask a question'.  Asking the right questions here will generally get you

I can't personally think of a clearer way to ask "does anyone know of
a low-side switch with current monitoring?"  Perhaps you could reprase
it in a way that makes it clearer, or did you reply the way you did
just to make yourself feel smart?  'Cause all you've done is make yourself
look like a bit of a dope.

--
Trevor Barton

 0
Reply tmb (57) 3/14/2005 4:09:47 PM

Richard Henry wrote:

> I need to make a heater circuit more intelligent.

Ok, but to do exactly what?

The existing design uses
> a low-side switch with with a simple logic feedback to check for proper
> operation.

Some safety feature, perchance?

An objective is to replace that with a device that will provide
> a voltage output proportional to the heater current.
>

Not proportional to temperature?  Just why do you need to know the current?

> I have found a few high-side switches that will do the job and I am starting
> to lean that way.
>

Don't mean to be rude here, but this is a great example of 'how not to
ask a question'.  Asking the right questions here will generally get you

--
Luhan Monat (luhanis 'at' yahoo 'dot' com)
"The future is not what it used to be..."
http://members.cox.net/berniekm

 0

Sounds like a "sensefet".  Does IR still make those?

In article <39lnlhF60b04mU1@individual.net>, rphenry@home.com says...
> I need to make a heater circuit more intelligent.  The existing design uses
> a low-side switch with with a simple logic feedback to check for proper
> operation.  An objective is to replace that with a device that will provide
> a voltage output proportional to the heater current.
>
> I have found a few high-side switches that will do the job and I am starting
> to lean that way.

 0
Reply DontSend2337 (3) 3/14/2005 4:38:56 PM

IR website search engine doesn't return anything for "sensefet".

One of the parts I am looking at is the IR3312S.  From the data sheet and
appnote, it requires an external FET to translate the input signal from
was not originally looking for) is that the feedback current resistor can be
used to set the overcurrent limit.

"Ol' Duffer" <DontSend@MeSpam.net> wrote in message
news:MPG.1c9f881284e477ea9896ac@news.bright.net...
> Sounds like a "sensefet".  Does IR still make those?
>
> In article <39lnlhF60b04mU1@individual.net>, rphenry@home.com says...
> > I need to make a heater circuit more intelligent.  The existing design
uses
> > a low-side switch with with a simple logic feedback to check for proper
> > operation.  An objective is to replace that with a device that will
provide
> > a voltage output proportional to the heater current.
> >
> > I have found a few high-side switches that will do the job and I am
starting
> > to lean that way.


 0
Reply rphenry (125) 3/14/2005 4:47:03 PM

Richard Henry wrote:
> I need to make a heater circuit more intelligent.  The existing design uses
> a low-side switch with with a simple logic feedback to check for proper
> operation.  An objective is to replace that with a device that will provide
> a voltage output proportional to the heater current.
>
> I have found a few high-side switches that will do the job and I am starting
> to lean that way.
>
>
Why not just a big MOSFET with a small resistance in the source lead,
plus a low-offset opamp?

--

Tim Wescott
Wescott Design Services
http://www.wescottdesign.com

 0
Reply tim261 (895) 3/14/2005 4:47:50 PM

On Mon, 14 Mar 2005 07:07:28 -0800, "Richard Henry" <rphenry@home.com>
wrote:

>I need to make a heater circuit more intelligent.  The existing design uses
>a low-side switch with with a simple logic feedback to check for proper
>operation.  An objective is to replace that with a device that will provide
>a voltage output proportional to the heater current.
>
>I have found a few high-side switches that will do the job and I am starting
>to lean that way.
>

What sort of current are you talking about ? Maximum voltage ?
Philips, ST Electronics and International Rectifier has these sort of
devices.

Regards
Anton Erasmus


 0
Reply nobody62 (615) 3/14/2005 6:01:49 PM

On Mon, 14 Mar 2005 07:07:28 -0800, Richard Henry wrote:

> I need to make a heater circuit more intelligent.  The existing design uses
> a low-side switch with with a simple logic feedback to check for proper
> operation.  An objective is to replace that with a device that will provide
> a voltage output proportional to the heater current.
>
> I have found a few high-side switches that will do the job and I am starting
> to lean that way.

Good Luck!
Rich


 0
Reply richgrise (94) 3/14/2005 6:58:42 PM

In article <39ltgaF6404f3U1@individual.net>, rphenry@home.com says...
> IR website search engine doesn't return anything for "sensefet".

I guess I'm dating myself...
It appears they have changed the name to "hexsense", and
their search engine isn't very useful.
They make 5-leg TO-220 and TO-247 package devices,
IRC730 for example.

 0
Reply DontSend2337 (3) 3/14/2005 7:20:02 PM

Anyone figure out if this is an AC or a DC current sensing requirement ?
What kind of Amps too ?

Makes a big difference how to constuct what is required !

Jay


 0
Reply invalidjbmiller (62) 3/14/2005 8:22:33 PM

Trevor Barton wrote:
> On Mon, 14 Mar 2005 08:21:39 -0800, Luhan Monat wrote:
>
>>Richard Henry wrote:
>>
>>
>>>I need to make a heater circuit more intelligent.
>>
>>Ok, but to do exactly what?
>
>
> To monitor the current going to the heater, as he says below.
>
>
>>  The existing design uses
>>
>>>a low-side switch with with a simple logic feedback to check for proper
>>>operation.
>>
>>Some safety feature, perchance?
>
>
> Does it matter in the context of the question?
>
>
>>   An objective is to replace that with a device that will provide
>>
>>>a voltage output proportional to the heater current.
>>>
>>
>>Not proportional to temperature?  Just why do you need to know the current?
>
>
> Can you truly not think of any good reasons for wanting to monitor
> the heater current?  Ah well chalk it up to either a lack of imagination
> or a lack of experience.  How is the reason he wants to monitor the
> current relevant to the question?
>
>
>>>I have found a few high-side switches that will do the job and I am starting
>>>to lean that way.
>>>
>>
>>Don't mean to be rude here, but this is a great example of 'how not to
>>ask a question'.  Asking the right questions here will generally get you
>
>
> I can't personally think of a clearer way to ask "does anyone know of
> a low-side switch with current monitoring?"  Perhaps you could reprase
> it in a way that makes it clearer, or did you reply the way you did
> just to make yourself feel smart?  'Cause all you've done is make yourself
> look like a bit of a dope.
>
>

I stand by my remarks.  Like many things I've seen on this NG, it lacks
some overall context for the questions being asked. At least, it
honestly seemed that way to me. If I'm wrong here, well, thats the way
things work here - after some back-and-forth bantering, some useful
information usually emerges overall.

--
Luhan Monat (luhanis 'at' yahoo 'dot' com)
"The future is not what it used to be..."
http://members.cox.net/berniekm

 0

Trevor Barton wrote:

> Can you truly not think of any good reasons for wanting to monitor
> the heater current?  Ah well chalk it up to either a lack of imagination
> or a lack of experience.  How is the reason he wants to monitor the
> current relevant to the question?
>

Would it not be better to know whether the heater here is used to heat a
fish tank or regulate blood temperature in a heart-lung machine?

I can *imagine* altogether tooooo many posibilities here.  If this were
a paying client asking the original question, I would certainly want to
know exactly what the heater was part of.  For liablility reasons for
starters.

--
Luhan Monat (luhanis 'at' yahoo 'dot' com)
"The future is not what it used to be..."
http://members.cox.net/berniekm

 0

In article <39lnlhF60b04mU1@individual.net>, rphenry@home.com says...
> I need to make a heater circuit more intelligent.  The existing design uses
> a low-side switch with with a simple logic feedback to check for proper
> operation.  An objective is to replace that with a device that will provide
> a voltage output proportional to the heater current.
>
> I have found a few high-side switches that will do the job and I am starting
> to lean that way.

Given the description I suspect Allegros devices are too large and
probably too expensive but you may want to have a look.

http://www.allegromicro.com/hall/currentsensor.asp

Then again maybe not, I see they go as low as 5A now.

Robert

 0

12 Replies
47 Views

Similar Articles

12/12/2013 5:37:55 AM
[PageSpeed]

Similar Artilces:

CAT6509 router or L3 switch? alternative Low-end L3 switches/router?
Is CAT6509 a router or an L3 switch? If it is an L3 switch/router, what is its equivalent router/L3 switch available from Cisco? I basically want to compare the Price details here. Also, I assume CAT6509 is a high-end router/L3 switch. What are the low-end alternatives here? qazmlp1209@rediffmail.com wrote: > Is CAT6509 a router or an L3 switch? > If it is an L3 switch/router, what is its equivalent router/L3 switch > available from Cisco? > I basically want to compare the Price details here. > > Also, I assume CAT6509 is a high-end router/L3 switch. What are the > low...

Looking for low-cost protoboards.
Hi, I was looking for some low-cost FGPA board for a home project. What I need it to have is -USB 2.0 -Analog output/input (either) -optionally several switches, leds, maybe display, but not necessary if has nice software control -possibly pins to access FPGA ports directly, like a 40 or 50 pin connector What I've found so far is http://www.opalkelly.com/ - nice looking small board for under \$200, which does not have analog ports. Thank you in advance Hi, protel demo board ? http://www.altium.com/livedesign/ usmgn "lomtik" <lomtik@gmail.com> a �crit dans le message d...

GE Low Voltage Switching -- Why Rectifier
I have a GE Low Voltage switching system installed in my house and note that the transformer is followed by a rectifier. What is the purpose of the rectifier. It seems that switching could be accomplished with AC pulses as well. ...

Looking for RMS AC current sense
Hey folks, I want to sense AC line current and supply the RMS value to a micro A/D input; 0-50A AC input current corresponding to 0-5V output. This has to have been done a gazillion times; does anyone have a link to an appnote handy or something? I'd ideally like to find a low-cost clamp on CT or hall effect device too; I don't want a series resistor. Any input appreciated! John Harlow wrote: > Hey folks, > > I want to sense AC line current and supply the RMS value to a micro A/D > input; 0-50A AC input current corresponding to 0-5V output. This has to > ...

Looking for remote RS-232 switch
I am looking for a remote RS-232 switch. This would be used to control multiple automation controllers in the basement wiring room from my 2nd floor office - a run of about 100 feet. The following automation devices need to be controlled over RS-232: Stargate, HMS 1020, Lutron HWI lighting system and Panasonic 1232 digital telephone system. No doubt there will be more! At the moment I'm using a Minicom RS-232 extender which uses standard CAT5 wiring with RJ-45 connectors. I'm not sure if I need the Minicom for the distance but it's sure handy to connect a DB-9 and CAT-5 into t...

Low impedence DVI-I A/B Switch
Greetings! I'm looking for a low impedence DVI-I A/B Switch. I've tried a couple that the local altex had to offer and no dice, these were a powered KVM (startech) and a mechanical switch from philmore/vanco. It seems that the impedence of both switches was too high, around 5 ohms across the powered switch and 3ohms across the mechanical (a little suprising). Using really short DVI-I cable we probably need something less than 2 ohms through the switch (the system can tolerate the loss equivalent to 10m of standard DVI cable). Some background. This is a kinda strange application where...

looking for a RPG with low system requirements
basically looking for some entertainment on my laptop during my new lengthy train rides. I haven't played an RPG in many many years (like Wizardy and Bard's Tale, I mean YEARS) so it doesn't have to be cutting edge because ANYTHING is gonna look great to me, I'm used to text for Pete's sake. I'm thinking like something from the discount bin that won't stress my low end specs. Or a game several years old that I might be able to just download for free from somewhere. what are some names I should look for ? have 256 RAM, 1500 mhz processor, the basic low end graph...

Look for cheap/used Layer 3 Switch
I'm helping a small college that has around 10 buildings connected via 100FX Ethernet. All of the buildings collapse to a central hub and is a flat layer 2 network. I'm would like to segment each building with a VLAN/subnet using some used Layer 3 Cisco switches. I'm not sure if any of the 2900xl or 3512xl switches can perform inter-VLAN routing. I will have each building collapse to a layer 2 core and performing the routing on the layer 3 switches for cost purposes (can't afford a 6513!!). If anyone can recommend an older model Cisco switch or router that can perform rout...

Junior webmaster looking for a job with low salary.
I'm Mohammed Ebied an Egyptian junior webmaster with good experience in online marketing. I'm looking for a job in any of the following positions junior web designer, junior web developer or online marketer. I've good experience in HTML/XHTML, CSS, JavaScript, Photoshop, SQL, & MySQL and basic knowledge of PHP, ASP.net, XML, Flash, Joomla, OsCommerce & WordPress. I also have experience in learning and excelling at new technologies as needed. My email is ebied4ever@gmail.com. I can be reached anytime via my cell phone, +20109598811 or via my msn ebied4ever@hotmail.com. ...

Bevel/Or? Effects on side (glass looking image), help :\
How does one achive something like this http://mchost.com/img/newlogo.gif with photoshop? That glass looking fade, I can't get it to work :\ any tips are greatly appreciated. <internet2@gmail.com> wrote in message news:1112155581.047957.297920@g14g2000cwa.googlegroups.com... > How does one achive something like this > http://mchost.com/img/newlogo.gif with photoshop? > > That glass looking fade, I can't get it to work :\ any tips are greatly > appreciated. Look into layer effects: Bevel, emboss, drop-shadow and gradient layers, filters-render effects. inte...

I am looking for some DSL news letters to know what is happening in Technology side, also dsl implementtaions?
Guys: I am looking for some DSL news letters to know what is happening in Technology side, also dsl implementtaions in worldwide, appreciated for any imputs, thanks in advance. Hi, You can still check www.networkingland.com/dsl_news.htm for DSL news letters or updates. Panda, www.networkingland.com GS wrote: > Guys: > > I am looking for some DSL news letters to know what is happening in > Technology side, also dsl implementtaions in worldwide, appreciated for > any imputs, thanks in advance. Try dslprime.com, which is a monthly newsletter. King GS wrote: > Guys...

Does the configuration my ISP provided make sense? If so, how should I configure my Cisco switches to properly utilize the Bridge being implemented with a connection to the internet at each buil
Hi all, I am quite new to the world of Networking and have just started a new job which is smack dab in the middle of a major project. The goal of this project is to migrate all physical server hardware to VmWare virtual servers as well as migrate those new virtual servers to a secure locations hosted by another company (Our ISP). My understanding is that the future network is being provisioned based on the requirement that we are able to failover to our head office in the case of a major failure at either the remote host site or the connection between the two buildings. Basically, th...

My switch is not switching
Hi, To handle a custom protocol over a serial line I am trying to implement a very small and simple state machine. The states are declared as enum: enum CommState { CS_WAIT_FOR_STX, CS_WAIT_FOR_T, CS_WAIT_FOR_0, CS_WAIT_FOR_Key, CS_WAIT_FOR_ETX }; I wanted to switch on the current state and handle whatever needs to be done in that state plus the transition to the next one. However, my switch() is always falling through to the default case. I have cut down my code to this nonsensical example: CommState commState=3DCS_WAIT_FOR_STX; if (commState=3D=3DCS_WAIT_FOR_STX) { s...

side by side concatenation
I have an output RowId Col1 Col2 Col3 ... ... ... ... -------------------------------------- RowId Col4 Col5 Col6 .... ... ... ----------------------------------------- I am trying to write a perl script to make it.. Row Id Col1 Col2 Col3 Col4 Col5 Col6 any advice??? thanks to everyone who responds.... man.postman@gmail.com wrote: > I have an output > > RowId Col1 Col2 Col3 > .. > .. > .. > .. > > > -------------------------------------- > > RowId Col4 Col5 Col6 > > ... > .. > .. > > ---------------------------------...

sorting side by side
I know there must be a way to do this using stl functions and not reinventing the sort loops and such but I need to sort several arrays side by side using one as the "key". Interested in ideas here... Two directions I can think of would be to create some sort of iterator or to create an object to wrap the value and index of the key array and then place these in a vector and sort it. Creating an iterator seems like maybe too complex but would probably be the more efficient way...maybe it could be generalized enough to use again sometime. It would certainly teach me more about iter...

Switch Within A Switch
Hello, I am working on an Adobe Acrobat file that uses javascript for calculations. I am trying to create a field that uses two other fields to determine a number value. I think this requires a switch within a switch, but I am not sure how to do this, as I am a beginner when it comes to javascript. In esscense, I want to set up a code so that each case of value A is calculated at each case of value B. Example: There are 9 cases for value A. There are 30 cases for value B. I want to produce a number at each value B for each case in value A. I hope I have explained what I want to do well e...

lstlistings side by side
Hi, to insert some computer source code into my latex document, I use the command "\begin{lstlisting}". How to I get two source codes being placed side by side instead of one below the other? Thank you. Regards, Chris Christian Christmann wrote: > to insert some computer source code into my latex document, I use the > command "\begin{lstlisting}". > > How to I get two source codes being placed side by side instead of one > below the other? put two minipages side by side Herbert -- http://TeXnik.de/ http://PSTricks.tug.org/ ftp://ftp.dante.de/tex-a...

[OSX] side by side python
Can I install Python 2.7 and 3.2 (from python.org) side by side on OSX without them stepping all over each other? On Mar 21, 9:31=A0am, Robert <sigz...@gmail.com> wrote: > Can I install Python 2.7 and 3.2 (from python.org) side by side on OSX > without them stepping all over each other? Yes, sure! Look for "python environment" http://pypi.python.org/pypi/virtualenv Regards Thanks! Oh, how do you like Sparrow vs Mail.app? On Mon, Mar 21, 2011 at 9:30 AM, FELD Boris <lothiraldan@gmail.com> wrote: > Yes, no problem. Follow the installation nor...

CNA51 and CNA41
Hi, I now have my new CNA51 sat beside my old CNA41. The sticker on the CNA51 and VERSION on it both report CNA51, but with a few different digits at the end. Initial impressions - the press feel of the keyboard is *marginally* softer on the CNA51, but not a lot in it really. The CNA5 seems to have a slightly more positive feel but it would be hard to notice unless you were looking for it. Overall then - little difference if any. It may just be the placebo effect brought on by the smell of the new case :-) The CNA51 still has the keys secured with a single small plastic tab at the top, as d...

ARE You looking for Employment and looking to have business
Well i have an online business for you that would change all that ..... make money, work anytime you want... and still keep your job.. Sign up and Try this ...................refund accepted.. https://paydotcom.com/r/24723/qualityproduct/2868603/ https://paydotcom.com/r/31112/qualityproduct/2868702/ https://paydotcom.com/r/31112/qualityproduct/2868717/ https://paydotcom.com/r/11825/qualityproduct/2868772/ https://paydotcom.com/r/9809/qualityproduct/2868789/ ...