Apparatus for displaying a band representation of a signal
AssigneeAlfred Herbert Limited
InventorRory Morgan O'Brien
Life of this patent
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Abstract
Apparatus for displaying a band representation, e.g. a bar graph or column graph, of a signal comprises a series connected array of light-emission devices such as LED.s and a preferably constant current source connected to one end of the series. Transistorised control means is arranged to bypass the constant current around selected ones of the devices in dependence upon the magnitude of an input signal to be displayed so that the devices remaining lit form a band representation of the signal. A center-zero display is provided by applying an offset voltage to the input signal.
Claims14
Band representation display apparatus comprising:
- a plurality of electrical light-emission devices which are physically positioned for forming a band representation and which are electrically connected in series with one another,
- electrical current supply means which is connected to one end of the series of light-emission devices and which is operable for making electrical current available to flow through the series to light the devices,
- control means including a plurality of switch means, which switch means are connected across respective associated ones of said devices and which are each operable for bypassing said continuous electrical current past the associated device,
- a conductive portion for receiving an input signal of which a band representation is to be displayed, and
- feedback means which is connected to said series arrangement and which is operable for delivering a negative feedback signal representative of the sum of the potential difference(s) across the lit light-emission device(s),
- said control means being connected to said conductive portion and said feedback means to receive said input signal and said negative feedback signal, and being operable to bypass said current past a number of said devices in dependence upon said input signal so that a band representation of said signal is formed by the devices remaining lit.
Dependencies are inferred from the claim text.