2004 IRISH SCIENTIST YEAR BOOK

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Abbey Grammar Christian Brothers� School, Newry, Co. Down
Donal Myles & Rory O Rourke
Ladder leveller

Donal Myles and Rory O�Rourke at the Exhibition

The idea for our project came about when one of Donal�s Uncles had an accident on a ladder whilst working on a construction site. He is fortunate to be alive, because from our research of statistics of ladder accidents we were shocked to find that in a fall from eleven feet or more 50% are fatal. The main reason for the majority of ladder accidents is that the user has not set up the ladder correctly. That is why we decided to design and manufacture a device that will allow the user to set up a ladder on uneven ground and help the user to set the ladder against the wall at the correct angle of 73 degrees which we found out through our research.

The device is constructed out of aluminium which is lightweight and portable but with a high tensile strength. The majority of the manufacturing took place in the school workshop: however we did require some specialist work to be carried out, like the welding of the aluminium, which we got done in a local engineering factory.

The circuitry for the project is quite simple yet effective. It involves the use of a quad op-amp circuit in the window comparator arrangement. There are two subsections in the circuit. The first deals with the level of the ladder, and this is done by the addition of two mercury tilt switches at either end of the device. When the ladder is level, the input voltage to the op-amps falls between the allowed window of voltages and an amber LED comes on to alert the user. However if the device is tilted, a red LED comes on to tell the user what is wrong and which way to correct the level.

The second part of the circuit deals with the angle of the ladder, and this is calculated by a potentiometer attached to the leg holders of the ladder and, as the angle is changed, the input voltage to the op-amps changes also. When the voltage is in the allowed window, an amber LED comes on, but if the angle is too obtuse or acute a red LED comes on to tell the user which way to adjust.

A series of logic gates follows the two opamps and, when the two voltages are between the allowed windows, a green LED comes on to indicate that both level and angle are OK.

We hope one day to take this idea further and mass produce the project which, in turn, will hopefully save lives.

Donal Myles & Rory O Rourke entered their project in the Senior Group Section in the Technology Category at the EsatBT Young Scientist & Technology Exhibition in January 2004. Their teacher was Mr Gerald Savage. They won a special award presented by the Patents Office.


This article was sponsored by the Patents Office