www.megadrum.info

Hey all,
I have read many threads on building a hall effect sensor for the hi-hat+ megadrum but my question is this,
What type of sensor should it be? Linear, Bipolar, Unipolar, Latch or omnipolar? And what about output current? And voltage?
Sorry for all the questions but on the website I am going to buy the sensor from there are soo many diferente types...
I will be using a hard drive magnet.
Thanks

http://www.akizukidenshi.com/catalog/g/gI-07014/

I bought this here. works great.

chain wrote:Hey all,
I have read many threads on building a hall effect sensor for the hi-hat+ megadrum but my question is this,
What type of sensor should it be? Linear, Bipolar, Unipolar, Latch or omnipolar? And what about output current? And voltage?
Sorry for all the questions but on the website I am going to buy the sensor from there are soo many diferente types...
I will be using a hard drive magnet.
Thanks

I finished my HH pedal with Hall effect and I am very content with results.
Here is what I have:
Sensor and magnet:

- sensor A1302KUA-T from http://uk.farnell.com/allegro-microsyst ... A1302KUA-T.
- sensor specifcations:

SENSOR, HALL EFFECT, LINEAR, 3SIP
Hall Effect Type: Linear
Output Current: 10mA
Sensor Case Style: SIP
No. of Pins: 3
Supply Voltage Min: 4.5V
Supply Voltage Max: 6V
Operating Temperature Min: -40°C
Operating Temperature Max: 125°C
Accuracy %: 3%
Operating Temperature Range: -40°C to +125°C
SVHC: No SVHC (16-Dec-2013)
Supply Voltage Range: 4.5V to 6V
- 2 magnets MAGNET NDFEBB (magnet diameter 8 mm, magnet length 15 mm, total length for 2 magnets 30 mm) one after another, from http://www.tme.eu/en/katalog/?idp=1&sea ... rameters=1 or from http://uk.farnell.com/meder/ndfeb-8x15m ... dp/1079500.

Megadrum settings:

- HH Pedal Switch (SW1) - Low impedance
- Alt input - checked
- Low level - 40
- High level - 450
- Curve - LiniarCustom1

How is functioning:

- magnet travel, from the moment when first line from MD display disappear and till when the closing sound is heard, is more than 30 mm and I think that this travel is absolutely satisfactory.
- minimum distance between magnet and sensor, when completely closed (after you already heard HH closing sound), is more than 3 mm, enough for protection of sensor.

Thanks so much!

chain wrote:Thanks so much!

Welcome ...

Ok, so my sensor has just arrived
Now my question is, what is the schematic you use to wire it to the tsr jack?
Thanks

Hello,

I think in this article you find all about your project.....

viewtopic.php?f=3&t=881&hilit=hall+effect+sensor

br

Nepo

Some info about wiring and pin-outs:

My Hall sensor box.

I glued the sensor on the inside of the box cover.
As the thickness of box cover is 1,5 mm and the distance between sensor and magnet after the Hi Hat closing sound is heard is 3 mm this means that distance between magnet and box cover will be 1,5 mm. This is enough good, magnet will not touch the box.

Thanks so much for all the info!
I will start wiring tomorrow and opening an old hard drive to extract the magnet,
Very excited to see if it works

chain wrote:Thanks so much for all the info!
I will start wiring tomorrow and opening an old hard drive to extract the magnet,
Very excited to see if it works

But chain why you did not bought the magnets I recommended you? They are cheap and strong. They are produced from neodymium (NdFeB) which is one of the best materials for magnets.
Look here to see characteristics of different materials:
http://www.mmcmagnetics.com/magdsgn/propcomp.htm
Also the diameter of recommended magnets, 8 mm, make the magnetic flux to be very tight, exactly what is needed.
Anyway, when you do the test please put here your experience.

One more thing, the wiring will work perfect if the Hi Hat pedal connector from MegaDrum is also correctly wired.
Here is a piece of Dmitri schematics showing tip/ring/sleeve connections as well as the position of the pedal select switch for high impedance and low impedance.

Regards,