DE4208469A1

DE4208469A1 - Using solar cell module as light sensor - using diode to decouple module from circuit and rechargeable battery, and taking light-dependent voltage directly from solar module terminals

Info

Publication number: DE4208469A1
Application number: DE19924208469
Authority: DE
Inventors: Peter Schwarz
Original assignee: Individual
Current assignee: Individual
Priority date: 1992-03-17
Filing date: 1992-03-17
Publication date: 1993-09-30

Abstract

In control circuits having a light-dependent function powered by a solarcell and battery (Akku) the circuit may be simplified by employing the solarcell as a light sensor for generating a switching signal (Schaltsignal). E.g. in a twilight sensing circuit, the output voltage (U) of the solarcell is directly compared with a reference voltage (Uref) in a comparator stage decoupled by the diode. The diode may be dispensed with and a current reference via the shunt resistor used, whose volt drop is amplified before input to the comparator and whose polarity indicates daylight/darkness depending on the direction of current flow to/from the battery (Akku). ADVANTAGE - Enables separate light sensor to be eliminated in circuitry where solar powered light-dependent function is required.

Description

In Steuer- und Regelsystemen, welche eine lichtabhängige Funktion beinhalten und deren Stromversorgung über Solarzellen geschieht, kann zur Schaltungsvereinfachung die Solarzelle auch als Lichtsensor verwendet werden. Hierbei muß entweder der Strom zwischen Solarzelle und elektronischer Schaltung gemessen werden, oder die Spannung am Solarmodul.In control and regulation systems, which have a light-dependent function contain and whose power supply takes place via solar cells, can also simplify the circuit as a solar cell Light sensor can be used. Here either the current be measured between the solar cell and the electronic circuit, or the voltage on the solar module.

I) Soll die Solarzelle als Dämmerungssensor dienen, so genügt es den Stromkreis mittels Diode zu entkoppeln. Bei Dunkelheit sinkt der Strom auf Null und entsprechend die Spannung (U) an der Solarzelle. Diese Spannungsänderung kann sehr leicht einem Komparator zugeführt werden um ein Schaltsignal zu erhalten. (Fig. 1)I) If the solar cell is to serve as a twilight sensor, it is sufficient to decouple the circuit using a diode. In the dark, the current drops to zero and, accordingly, the voltage (U) on the solar cell. This voltage change can very easily be fed to a comparator in order to obtain a switching signal. ( Fig. 1)

II) Soll die Solarzelle der Lichtmessung während des Tages dienen, so kann der Strom von der Solarzelle in die Batterie gemessen werden. Je nach Stromstärke, läßt sich der gewonnene Spannungsabfall an einem Shuntwiderstand verstärken und wiederum einem Komparator zuführen um ein Schaltsignal zu erhalten. (Fig. 2)II) If the solar cell is used to measure light during the day, the current from the solar cell into the battery can be measured. Depending on the current strength, the voltage drop obtained can be amplified using a shunt resistor and in turn fed to a comparator in order to obtain a switching signal. ( Fig. 2)

III) Soll der Strom bei Dämmerung gemessen werden, ohne eine Diode zu verwenden, so kann bei Verwendung eines Akkus der Rückstrom I₁ vom Akku in das Solarmodul über einen Shuntwiderstand gemessen werden und nach Verstärkung zur Ansteuerung eines Komparators verwendet werden. (Fig. 3)III) If the current is to be measured at twilight without using a diode, the return current I 1 from the battery into the solar module can be measured via a shunt resistor and used after amplification to control a comparator when using a battery. ( Fig. 3)

Claims

1. The use of a solar cell module as a light sensor. In which the module via a diode from the rest of the circuit and battery is decoupled and a light-dependent voltage directly to the Voltage connections of the solar module is obtained.

2. The use of a solar cell module as a light sensor, whereby the module is connected directly or decoupled to the circuit is and a light-dependent signal by measuring the current is obtained, the current from the solar module in the Circuit, including battery flows.

3. The use of a solar module as a light sensor, the Module is connected directly or decoupled to the circuit and by measuring the reverse current, a light-dependent signal is obtained, the current from the battery or the circuit in the solar module flows back.