GB2254140A - Electronic spirit level - Google Patents

Abstract

The spirit level comprises two identical units each consists of a switching I.C. 22 with 8 inputs and 8 outputs (Darlington Transistor Arrays). The inputs are connected to 5 L.D.Rs 23 that would through the change of resistance switch the relevant output ON or OFF. The L.D.Rs are placed at a particular angle on top of a spirit level tube containing dark liquid, the L.D.Rs facing 5 continuously lit L.E.Ds at the mentioned angle, and only when the air bubble passes between the two, light from the L.E.D is reflected at the other side of angle thus activating the L.D.R which in turn would switch on the output which is connected to indicating L.E.Ds, audible sound being provided by means of a sounder connected in parallel with the centre output. <IMAGE>

Description

AUDIBLE ELECTRONIC SPIRIT LEVEL This invention is an electronic audible spirit level, designed to give a bright visual indication of the vertical and horizontal levels, via light Emitting Diods (L.E.Ds), with loud audible sound via a small electronic sounder when the level is indicating absolute centre.

Unlike the traditional spirit level, which has to be monitored by looking directly at it and in reasonable light, the sound from this electronic spirit level would enable one to level any thing without having to be looking at it at all, unlike for example, when one person is using the traditional type of spirit level and has to go up and down while adjusting the article, i.e, a snooker table, or similar things with adjustable feet far away from the top to be levelled absolutely horizontal, or else one must have another person to monitor the level for centre.

This electronic spirit level consists of two small and identical P.C.Bs (Fig 1, Nos 1 & 2/P.1).

The heart of the unit is a Darlington Transistor Arrays in an IC form, having 8 inputs and 8 outputs, all outputs are connected to small 3mm L.E.Ds via resistors 1--8 (Fig 5, P.3), and 7 inputs connected to 5 L.D.Rs (Light Dependant Resistor) (Fig 5/P.3/23), while input No 8 is latched permanently by resistor R10.

The main idea is to detect the position of the air bubble in a tube similar to that of the conventional spirit level, and display the position visually via the L.E.Ds. Although simple, the idea would not work with the tubes used for the conventional spirit levels, unless as discovered and used in the working prototype the liquid has to be dyed black.

Circuit Connections Fig 5, Page 3 showing circuit diagram of the complete working unit, which has five 5 L.D.Rs connected to seven 7 inputs (F.5/P.3/23) pin 1-7, by linking input 2 & 3, and input 5 & 6, pin 8 connected to positive via R10 in order to turn output No 8 at pin 11 ON, immediately once the six volts power supply is switched ON, the output at pin 11 drives five clear red (3mum) L.E.Ds (via R 8) (Fig 4/P.2/20) which are fixed in position at an angle of (1500) towards the five L.D.Rs.

As shown in Fig 3, P.2, both components are soldered on two small strips of P.C.B glued together at the mentioned angle, so that every L.E.D serves only one L.D.R. As for outputs from Pin (12--18), F.5, they are connected as shown to the indicating L.E.Ds (via R1--7), and each output drives three (3) L.E.Ds.

Pin 12 drives three red L.E.Ds, Pin 13 drives two red L.E.Ds, Pin 14 drives one amber L. E . D, Pin (13 & 14) operate simultaneously due to Pin 5 & 6 of the input being linked together, Pin 15 drives three green L.E.Ds (centre indicators), also connected to Pin 15 the negative side of the electronic sounder, (bypassing the resistor R4), Pin 16 drives one amber L.E.D and operates simultaneously with Pin 17 which drives two red L.E.Ds, both outputs switch on together due to linking input Pins 2 & 3.

Pin 18 drives 3 red L.E.Ds.

Finally P.C.Bs 3 & 4 (L.E.Ds & L.D.Rs) shown in Fig 1. P.1 are connected to P.C.Bs 1 & 2, via hair thin gauge wires in order to allow flexibility and freedom of movement of the tube assembly.

No power consumption or battery drainage take place when the circuit is in the OFF position (SWl OFF).

The overall consumption when (SW1 is ON) is (55 mA) maximum, at centre, with the three green L.E.Ds and the electronic sounder.

HOW IT WORKS Referring to Fig 4, P.2/20, L.E.Dsl---5 are lit "continuously", and only when the air bubble is centrally opposite the corresponding L.D.R it receives the reflected light of the L.E.D, as it has been found that the surface of the cavity of the bubble works in a way similar to fibre optics, transferring the spot of light emitted by the L.E.D to the other side of the tube, only then the resistance of L.D.R changes, thus switching ON the corresponding input, which in turn, turns ON the L.E.Ds responding to its output, thus indicating visually the position of the air bubble, and if that was the centre which would be detected by L.D.R No 3 that will turn the input at Pin 4 and output at Pin 15 ON, the latter would light the three green L.E.Ds and activate the electronic sounder as it is connected in parallel with them.

The main components are soldered on the two separate P.C.Bs, each measuring 5 x 5 cm. The unit is powered by (4) four rechargeable batteries size AA.

Power connection is made as seen in Fig 5, P.3, via the main power switch (SW1) which has three positions OFF, Horizontal circuit ON, and both Horizontal and Vertical ON together via the micro switch (SW2).

If SW1 is in the Horizontal ON position, and the unit is turned to the vertical position, only then SW2 operates by switching OFF P.C.B 1 and turning ON P.C.B 2 for vertical indication.

When the two circuits are ON for horizontal indication for both directions, and in order to identify which circuit's sounder is indicating the centre and not to confuse its signal with the other sounder as in the case of frequency harmony, therefore, it has been designed that there is a frequency difference between the two sounders and that would enable the ear to identify the dissonance between the two notes confirming that the two circuits are at centre.

HOW IT WORKS (continued) In order to make the unit function correctly in all positions (i.e, tilting), the two tubes that contain the liquid are mounted on brackets via centre pins in the tubes to enable them to turn around and to keep the bubble in a permanent position aligned with the L.E.Ds and the detectors, and this can only be maintained by adding a weight of lead relevant to the weight of the detectors that are fixed on top of the tube, keeping in mind an addition in the lead weight by F time, this way making the best use of gravity and anti-gravity, as the lead will maintain its position due to gravity, and the air bubble will maintain a vertical position at all times as seen in Fig 3 & Fig 4.

The calibration bracket (No 17 Fig 3) moves in all directions controlled by adjusting screw and mounted on a strong bow shaped spring.

The complete spirit level measures 47 cm long, 7 cm wide, 3 cm deep.

DRAWINGS GUIDE Fig 1 Full assembly of the whole unit Fig 2 Top cover Fig 3 The swivelling spirit level tube in full assembly Fig 4 Side view of the tube and detectors Fig 5 Complete circuit diagram Fig 6 Printed circuit board PARTS & DESCRIPTION Nos 1 & 2 Main P.C.Bs with components Nos 3 & 4 Top view of the spirit level tubes with the P.C.Bs of the detectors No 5 Rechargeable batteries size AA Nos 6 & 7 Electronic sounders No 8 Micro switch No 9 Small lead weight No 10 Main switch (SW1) Nos 11 & 12 Sounders grid No 13 Calculator arid measurements convertor No 14 L.D.Rs (detectors) No 15 Spirit level tube No 16 Fixed bracket No 17 Adjustable bracket No 18 Calibeating screw No 19 Spring No 20 L.E.Ds 1 to 5 No 21 Lead weight No 22 I.C ULS-2800R (Darlington Transistor Arrays) No 23 L.D.Rs 1 to 5 No 24 L.E.Ds 6 to 20 No 25 L.E.Ds 1 to 5 No 26 Connections to switch SW1/1 No 27 SW1/2 No 28 Micro Switch Connection

Claims (19)

1. Electronic detecting unit for the measuring of levels in the horizontal and vertical positions comprising means for detecting the position of an air bubble in a glass tube.

2. Electronic detecting unit according to claim 1 providing electronic visual indication by means of L.E.Ds.

3. Detecting unit according to claim 1 or 2 and including loud audible sound when level is dead centre.

4. Detecting unit according to any of the preceding claims wherein said detecting means of reflected light from L.E.Ds through the air bubble and electronically translating its exact position into the indicators L.E.Ds.

5. Unit according to claim 4 wherein the detecting means include dyed liquid in the levelling tubes, so that light only passes through the bubble.

6. Unit according to claim 5 wherein provides design for swivelling movement of the levelling tube and detecting unit to provide fixed detecting point in all positions.

7. A method according to claim 1 and substantially as wherein described.

8. Electronic detecting method comprising two identical circuits and detecting units.

9. A method for levelling comprising electronic audible and visual indications.

10. A method according to claim 9 and substantially as described herein.

11. An electronic method for audible and visual indication of levels substantially as described herein with reference to the accompanying drawings.

Amendments to the claims have been filed as follows 1. A device for sensing the orientation of a surface against which it is placed, the device comprising an enclosed tube containing a main liquid and a bubble of a secondary fluid which is effectively immiscible with the main liquid, the longitudinal position of the bubble in the tube being dependent on the orientation of the device; light projecting means for projecting light at the tube at a balance point along the length of the tube, at which balance point the bubble is positioned when the device is at a desired orientation; light detecting means for detecting the presence of light projected by the light projecting means, after that light has been reflected by the bubble when the bubble is positioned at the balance point; and indicator means, operable to provide an external indication when the bubble is positioned at the balance point and light reflected by the bubble is detected by the light detecting means; wherein the main liquid is substantially opaque to light and the secondary fluid is substantially transparent to light, such that significant amounts of the light projected by the light projecting means may only be detected by the light detecting means when the bubble is positioned at the balance point.

2. A device according to Claim 1, wherein the main liquid is dyed black.

3. A device according to Claim 1 or Claim 2, wherein the light projecting means comprises an LED.

4. A device according to any one of the preceding claims, wherein the light detecting means comprises a light dependant resistor (LDR), which is sensitive to the presence or absence of light projected by the light projecting means.

5. A device according to any one of the preceding claims, comprising a plurality of light projecting means, each of which projects light for detection by a corresponding light detecting means in a plurality of light detecting means.

6. A device according to any one of the preceding claims, additionally comprising processing means, for processing signals received at the light detecting means so as to obtain an indication of the longitudinal position of the bubble in the tube and hence of the orientation of the device and of a surface against which the device is placed.

7. A device according to Claim 6, wherein the processing means comprises a microprocessor chip or its equivalent.

8. A device for sensing the orientation of a surface against which it is placed, the device comprising an enclosed tube containing a main liquid and a bubble of a secondary fluid which is effectively immiscible with the main liquid, the longitudinal position of the bubble in the tube being dependent on the orientation of the device and the bubble being positioned at a balance point along the length of the tube when the device is at a desired orientation; detection means sensitive to the longitudinal position of the bubble in the tube, for detecting when the bubble is positioned at the balance point; and indicator means, operable to provide an external indication when the bubble is positioned at the balance point; wherein the tube and the light detection means are mounted in the device in such a manner that the bubble remains, in use of the device, in a fixed radial orientation relative to the detection means whatever the radial orientation of the device in relation to the longitudinal axis of the tube.

9. A device according to Claim 8, wherein the tube is mounted in the device so as to allow radial rotation of the tube and the detection means relative to that part of the device to be placed against a surface whose orientation is to be measured.

10. A device according to Claim 9, wherein the tube is mounted in the device by means of centre pins in the tube.

11. A device according to any one of Claims 8-10, wherein the tube is weighted so as to return, under the influence of gravity, to the correct radial orientation, at which the bubble is in the fixed radial orientation relative to the detection means, whenever the tube is displaced from the correct radial orientation by movement of the device.

12. A device according to any one of the preceding claims, wherein the secondary fluid is air.

13. A device according to any one of the preceding claims, wherein the indicator means emits an audible signal.

14. A device according to any one of Claims 1-12, wherein the indicator means emits a visible signal.

15. A device according to Claim 14, wherein the indicator means comprises one or more light emitting diodes (LEDs).

16. Apparatus for sensing the orientation of a surface against which it is placed, comprising two devices, each according to any one of the preceding claims, wherein the tubes of the two devices are arranged so as to be mutually perpendicular in use of the apparatus.

17. Apparatus according to Claim 16, wherein the indicator means of the two devices emit distinguishable signals.

18. A device for sensing the orientation of a surface against which it is placed, substantially as herein described with reference to the accompanying illustrative drawings.

19. Apparatus for sensing the orientation of a surface against which it is placed, substantially as herein described with reference to the accompanying illustrative drawings.