coozer
|
 posted on 12/4/08 at 07:25 PM |
|
|
Speedo Pickup
Peeps, I have an Acewell unit that came with a magnet and reed switch. Not wanting to use that I've been trying all day to get this to work.
Its a hall effect senor off a Perjoe, it was looking at the starter ring on the bell housing so presume it was fro the ign?
Anyway, wiring it up to my Acewell today, allen key in the drill, woosh 240mph! However, fastening onto the car so it looks at the diff bolts i get
nothing 0.00mph
The output from the dash is only at 3.5V so will that reduce the effectiveness of the sensor?? I cant get it any bloody closer
Thoughts please peeps....
 
Rescued attachment speedo.jpg
1972 V8 Jago
1980 Z750
|
|
|
|
|
big_wasa
|
| posted on 12/4/08 at 07:32 PM |
|
|
I tried a Ford VR sensor on an Acwell and could not get it to work properly.
The read switch worked fine however.
|
|
|
coozer
|
| posted on 12/4/08 at 07:52 PM |
|
|
just been perusing the acewell site and came across this statement:
"The ACEWELL speedos are available with the following types of speed sensor as follows:
Sensors can be bought as replacement parts for £14.95 each. The part number in the speedo must be underlined to be able to work with hall effect and
mechanical drive speedos"
What does it mean were it says The part number in the speedo must be underlined to be able to work with hall effect
1972 V8 Jago
1980 Z750
|
|
|
02GF74
|
| posted on 12/4/08 at 08:02 PM |
|
|
If it is realy a Hall effect sensor that isn't going to work unless you can magentise the prop bolts. Hall effect detects magentic fields.
If it is a relucatance type sensor - these have a magnet built in with a coil around the magnet - a ferrous object passing close by - say a steel prop
bolt - will "distort" the magnetic filed generating voltage in nthe coil.
I have no idea what that sensor you have is - it may be neither of the two I have described.
|
|
|
paulf
|
| posted on 12/4/08 at 08:53 PM |
|
|
A hall effect type sensor would have 3 wires live, neutral and output.If your sensor has just 2 it is a magnetic reluctance sensor and will generate
an output of varying voltage depending on the speed of the target it is aimed at.
What you probably need is a 3 wire proximity switch which will give an output when near a ferrous object that is moving or stationary.RS sell them in
various sizes something like an 8mm thread woud do the job.
Paul.
|
|
|
coozer
|
| posted on 12/4/08 at 08:54 PM |
|
|
The sensor itself is magnetic, it sticks to the bolt heads and picks up filings etc. Doesnt work in position on the car but whizzing the allen in
drill past it gives me a display. I'm wondering whether the input voltage at 3.5V is too low.
1972 V8 Jago
1980 Z750
|
|
|
coozer
|
| posted on 12/4/08 at 09:02 PM |
|
|
I get the drift on what your saying there Paul. The sensor has two wires that connect to the Acewell, it supplys 3.5v to my two sensor.
From what your saying there i believe now it needs a good speed to pick anything up, hence the 240 mph on the drill!
Back to the supplied magnet and pickup me thinks.
What I was looking for was a locost solution for a robust speed sensor setup.
Cheers,
Steve
1972 V8 Jago
1980 Z750
|
|
|
paulf
|
| posted on 12/4/08 at 09:14 PM |
|
|
Ive had a cycle speedo fitted for over 2 years and had no problem with the sensor which is just a reed switch and magnet type.I mounted the sensor
with the supplied O rings and securely cable tied the cable to the wing stay so as it didnt put any strain on the sensor.For the magnet I got a small
magnet and glued it to the wheel rim with epoxy resin.
Paul.
|
|
|
matt_claydon
|
| posted on 12/4/08 at 09:48 PM |
|
|
If the sensor is magnetic then it's a VR (variable reluctance) sensor (like crank position or ABS wheel sensors) not a Hall effect. It should
not be supplied with a voltage as it produces it's own when metal objects pass nearby. These sensors produce an AC output voltage which is then
'decoded' by a processing circuit to produce a pulsed output that can be used by an instrument / ECU.
The fact you got a reading with the drill sounds like luck, it isn't the right sensor to use and you won't get a reliable reading from the
gauge. You need to get a proper hall-effect sensor or reed switch and put a magnet on the prop flange.
|
|
|
snapper
|
| posted on 13/4/08 at 04:05 AM |
|
|
I went with magnets and reed switch, four magnets araldited to the prop flange, simple and no problemd
I eat to survive
I drink to forget
I breath to pi55 my ex wife off (and now my ex partner)
|
|
|
.jpg)
