3 LED - 1 Cell battery tester


Posted on Feb 11, 2013    4639

The device serves to quickly establish the status of an indicative power cells. I built it for his children, so they can determine the degree of self-discharge batteries in a variety of toys. WAS tester designed to test the fast primary (zinc, alcaline) Cell. Contains simple voltage converter and level indicator. The tester is powered from tested cell. Supply current is depend of cell voltage at 1.5 V and is approx. 200 mA. For high efficiency voltage converting Must be a low saturation voltage transistor T1 Used. Polarity Tester Has Tolerant Input (max. 3 V). The tester is powered from the measured article is loaded with current of 200 mA.


3 LED - 1 Cell battery tester
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Differentiate between the "fresh" part of the old, which, while having sufficient open circuit voltage, but also a large internal resistance. Maximum input voltage is 3 V to the voltage tester is robust against reverse polarity. Tester is designed for primary cells. The measurement of NiCd and NiMH batteries due to a lower voltage LED2 lights up. The batteries are also in the discharge voltage decreases very slowly and the tester can not only determine if the battery is completely discharged. The test articles could be used as tester - "knives" with a bulb, but such a solution would be difficult to satisfy the amateur electronics. Described here indicates the battery tester of the number of lit LEDs. The involvement of the tester ( Fig. 1 ) can distinguish two parts: a voltage converter and the voltage level indicator. Since the LED needs a supply voltage of about 2 and a fresh battery has only about 1.55 V, was to be used in wiring the drive. The drive is samokmitající and uncontrolled output voltage is highly dependent on input voltage. This dependence is intentionally increased the use of dividers R1, R2 in the circuit database. A critical part of the drive transistor T1, which have a small saturation voltage. Otherwise, the efficiency rapidly deteriorates. As the transformer is standard radial choke on the secondary winding p?ivineme - about 30 turns enamelled wire with a diameter of about 0.2 mm. Despite the winding...




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