HobbyKing.com New Products Flash Sale
Reply
Thread Tools
Old Sep 21, 2010, 07:21 AM
ancora imparo
jj604's Avatar
Melbourne, Australia
Joined Jul 2005
6,783 Posts
Unfortunately the Temp sensor plugs into the Current sensor. You can't use it with the Tx alone.

John
Quote:
Originally Posted by HenryV View Post
I've browsed to the various posts about this Quanum gadget, but cant find the answer.
Can you also use just the temperature reading of the add-on current/temp sensor? Im not interested in current readings.

Or needs this add-on sensor its operating power from the power connection between lipo and ESC? I'm just interested in Temperature telemetry in my RC project en dont want the hassle of soldering the sensor in between the lipo's and batteries.

Thanks for reply up front.
jj604 is online now Find More Posts by jj604
Reply With Quote
Sign up now
to remove ads between posts
Old Sep 21, 2010, 02:41 PM
Registered User
Bill Glover's Avatar
United Kingdom, Bracknell
Joined Nov 2000
11,948 Posts
Got my temp/amps/mah add-on board and wire antenna today.

The add-on board and temp sensor (without battery connectors or heatshrink) totals to a fairly hefty 13.5 grams. Wire antenna is 4.9 grams vs 9.8 for the stock one.

For completeness the bare transmitter is 8.6 grams.

HenryV - to answer your question I'm 99.9% sure you can just use the temp sensor. Only the +ve line from the pack is connected to the add-on board (if you use 2-pin connectors e.g. Deans the -ve pins both connect to an isolated pad on the board that simply bridges them together and doesn't go anywhere else). So the board must be powered from the TX via the connector lead.
Bill Glover is offline Find More Posts by Bill Glover
Reply With Quote
Old Sep 21, 2010, 04:47 PM
Registered User
Joined Jul 2010
64 Posts
Thanks Bill !

@jj604, i do understand that I need the add-on board to use the temp sensor, but what I wanted to know if the "current part" of the add-on board was also used to power the add-on board and thus need to be soldered between the pack and ESC. But with the info from Bill the temp sensing part is powered by the Tx connector plug wich saves me soldering and hassle for something I dont need!
Thanks for your input though JJ604 !
HenryV is offline Find More Posts by HenryV
Reply With Quote
Old Sep 21, 2010, 07:16 PM
ancora imparo
jj604's Avatar
Melbourne, Australia
Joined Jul 2005
6,783 Posts
Ah! Sorry. Bill is correct. I didn't read your question carefully enough.

The three wires in the lead to the transmitter will be +5V, -Ve and signal. Both the temp and hall effect current sensor need a 5V supply and put out a what I presume is a combined serial data stream (or maybe "One-wire") on the orange wire (haven't looked at it). There is no physical connection between the main battery connectors and anything on the sensor board. The current passes straight through the main connectors on Hall Effect sensor.

Just check it works on the bench before you rely on it though as I'm not sure what the TX and or Rx will do if one of the data elements is missing on the input. It may just ignore it or it may get confused. Let us know how it goes.

BTW There is some discussion of connection issues with the external sensor on the other thread here:

http://www.rcgroups.com/forums/showthread.php?t=1192809
Quote:
Originally Posted by HenryV View Post
Thanks Bill !

@jj604, i do understand that I need the add-on board to use the temp sensor, but what I wanted to know if the "current part" of the add-on board was also used to power the add-on board and thus need to be soldered between the pack and ESC. But with the info from Bill the temp sensing part is powered by the Tx connector plug wich saves me soldering and hassle for something I dont need!
Thanks for your input though JJ604 !
jj604 is online now Find More Posts by jj604
Last edited by jj604; Sep 22, 2010 at 08:59 AM.
Reply With Quote
Old Sep 22, 2010, 07:10 AM
Registered User
Joined Jul 2010
64 Posts
Ok, my set (Quanum+temp+extra antenna) is in the mail now.
will post results here. Thanks again!
HenryV is offline Find More Posts by HenryV
Reply With Quote
Old Sep 22, 2010, 08:58 AM
ancora imparo
jj604's Avatar
Melbourne, Australia
Joined Jul 2005
6,783 Posts
Reducing weight.

Just a thought, but I ended up with some spare TX antennas when I bought two lightweight ones (and when I smoked a Tx - but that's another story )

I chopped one up and I think you could safely remove most of the outer cover. Inside there is quite a short wire that extends only 1/3 way up the outer cover. The rest is empty. If you carefully cut around the aerial just above the faint join line above the knuckle you are left with a short wire emerging from where the outer barid is soldered to a thin metal tube.

Worth a try. You end up with a lighter plastic nut than the add-on version and I bet it comes out overall significantly lighter and shorter than the add-on "lightweight" aerial.

Maybe I have missed some secret-RF-guys business here? Anybody got a comment?

John
jj604 is online now Find More Posts by jj604
Reply With Quote
Old Sep 22, 2010, 09:18 AM
Southern Pride
everydayflyer's Avatar
Haralson County GA. USA
Joined Oct 2004
34,834 Posts
John have you ever looked at the 2.4 receivers with whisker antennas on them? The antenna is just a length of coax with the shield connected to ground on the base end , the center connected to RF out at the base end and enough of the shield removed on the far end to expose a section for a 1/4 wave(?) length antenna.

It is not entirely that simple as different 2.4 antennas as used on routers and such do have different dB's of gain but as this a non critical application one could get by with most anything I would think.

Some have been known to use replacement router antennas on their 2.4 RC Transmitters even but I do not recommend that unless one really understands exactly what they are doing and of course in the US one would be in violation of FCC regulations as all transmitters have to be type accepted and the antenna is part of the said certification.

Charles
everydayflyer is online now Find More Posts by everydayflyer
Reply With Quote
Old Sep 22, 2010, 09:29 AM
ancora imparo
jj604's Avatar
Melbourne, Australia
Joined Jul 2005
6,783 Posts
Thanks, Charles. That's what got me thinking - the 2.4GHz Rx aerials. Why are the Quanum TX aerials so big - a wavelength is a wavelength after all? These things must all be 1/4 wave. Certainly the huge outer plastic cover on the QuanumTx aerial isn't connected to anything. It's just a physical casing. Inside is exactly what you describe. A shileded wire with a ~1" bare bit and the shield soldered to a metal tube. My guess is they simply used standard WiFi aerials to keep it cheap. 75% of it may be redundant waste weight.

I'm not suggesting folks modify or replace the antenna, just cut away the dead wood. But my expertise in RF is basically limited to putting things in the microwave so knowledgable advice is welcome.

John
Quote:
Originally Posted by everydayflyer View Post
John have you ever looked at the 2.4 receivers with whisker antennas on them? The antenna is just a length of coax with the shield connected to ground on the base end , the center connected to RF out at the base end and enough of the shield removed on the far end to expose a section for a 1/4 wave(?) length antenna.

It is not entirely that simple as different 2.4 antennas as used on routers and such do have different dB's of gain but as this a non critical application one could get by with most anything I would think.

Some have been known to use replacement router antennas on their 2.4 RC Transmitters even but I do not recommend that unless one really understands exactly what they are doing and of course in the US one would be in violation of FCC regulations as all transmitters have to be type accepted and the antenna is part of the said certification.

Charles
jj604 is online now Find More Posts by jj604
Reply With Quote
Old Sep 22, 2010, 09:58 AM
Registered User
Bill Glover's Avatar
United Kingdom, Bracknell
Joined Nov 2000
11,948 Posts
The lightweight antenna is only $4.95 at Hobby City, not really worth experimenting with DIY jobs unless you already happen to have spare antennas, connectors, etc, lying around.
Bill Glover is offline Find More Posts by Bill Glover
Reply With Quote
Old Sep 22, 2010, 11:00 PM
ancora imparo
jj604's Avatar
Melbourne, Australia
Joined Jul 2005
6,783 Posts
Bill, on reflection I totally agree.

I just weighed the various options.

A Quanum V1 is 6.1g
Standard antenna 10.0g
DIY standard modification with outer shell removed 7.1g
Lightweight antenna 4.8g

The only advantage of the DIY mod to the standard antenna is if you needed a really short one for some reason.

John
Quote:
Originally Posted by Bill Glover View Post
The lightweight antenna is only $4.95 at Hobby City, not really worth experimenting with DIY jobs unless you already happen to have spare antennas, connectors, etc, lying around.
jj604 is online now Find More Posts by jj604
Reply With Quote
Old Sep 23, 2010, 07:24 AM
Registered User
Bill Glover's Avatar
United Kingdom, Bracknell
Joined Nov 2000
11,948 Posts
Quote:
Originally Posted by jj604 View Post
The only advantage of the DIY mod to the standard antenna is if you needed a really short one for some reason.
Agreed - the lightweight one is longer than the standard antenna.

The stated 1 km range is overkill for most of us (FPV excepted), so losing some efficiency may not matter.

There's a post on the Hobby City forum which could be worth a try, depending on what you're flying
Quote:
A lighter antenne can be made very easy
just solder a 22 mm long wire to the middle of te connector plug.
measured range 250m now (is more than enough)
be carefull the sender is not mounted too close to your receiver!
Bill Glover is offline Find More Posts by Bill Glover
Reply With Quote
Old Sep 23, 2010, 07:55 AM
ancora imparo
jj604's Avatar
Melbourne, Australia
Joined Jul 2005
6,783 Posts
That's interesting. The wavelength at 2.4GHz is 125mm. 1/4 wave would be 31.25. Wonder where the 22mm came from?

Charles, you know about this stuff - any ideas?

John
Quote:
Originally Posted by Bill Glover View Post
Agreed - the lightweight one is longer than the standard antenna.

The stated 1 km range is overkill for most of us (FPV excepted), so losing some efficiency may not matter.

There's a post on the Hobby City forum which could be worth a try, depending on what you're flying
jj604 is online now Find More Posts by jj604
Reply With Quote
Old Sep 23, 2010, 07:23 PM
ancora imparo
jj604's Avatar
Melbourne, Australia
Joined Jul 2005
6,783 Posts
Just measured the active part of the aerial of a Quanum standard TX above wher the shield is soldered. It's 28mm. Someone else can expalin what all this means.

For anyone who would like to try the standard antenna but in a "short" version, you don't have to modify it at all. The outer case just pulls off with a bit of bending and twisting around the join line.

Photo attached which shows what it looks like when the push fit cover is removed. (It's a strong push fit though).
jj604 is online now Find More Posts by jj604
Reply With Quote
Old Sep 23, 2010, 09:59 PM
Southern Pride
everydayflyer's Avatar
Haralson County GA. USA
Joined Oct 2004
34,834 Posts
I measured the exposed antenna sections of a couple of my Fly Dream 2.4 receivers and they are 1.300" / 33.08 mm.

Charles
everydayflyer is online now Find More Posts by everydayflyer
Reply With Quote
Old Sep 24, 2010, 02:31 AM
Registered User
Son, Norway
Joined Sep 2004
3,362 Posts
I have pulled the top of many such antennas for RC use. Element lengths have been in the range 24-30mm. The metal sleeve is an element too (dipole). Seems that the philosophy is "not perfect, but good enough" .

Fred
flarssen is online now Find More Posts by flarssen
Reply With Quote
Reply


Thread Tools

Similar Threads
Category Thread Thread Starter Forum Replies Last Post
Discussion Quanum battery voltage telemetry - and 'voltage under load' question ... JJJNYC Batteries and Chargers 51 Oct 22, 2014 12:55 PM
Cool Picked this up at the post office last night. The Quanum 2.4ghz lipo telemetry unit cryhavoc38 Batteries and Chargers 282 Dec 11, 2012 09:26 PM
Question Quanum 2.4ghz Telemetry DjBac Batteries and Chargers 21 Nov 29, 2010 03:43 PM
Alert $70 BUCKS! Quanum 2.4Ghz voltage telemetry (1km Range) jet-ster Foamy EDFs 42 May 28, 2010 12:54 AM
Discussion quanum 2.4 ghz telemetry sellman Electric Plane Talk 3 Mar 29, 2010 12:00 PM