This is the circuit diagram of a simple bane chargeless baptize akin indicator for home and industries. In actuality the the akin of any conductive non acerb liquids can be abstinent application this circuit. The circuit is based on 5 transistor switches. Anniversary transistor is switched on to drive the agnate LED , if its abject is supplied with accepted through the baptize through the electrode probes. One electrode delving is (F) with 6V AC is placed at the basal of tank. Next probes are placed footfall by footfall aloft the basal probe. If baptize is ascent the abject of anniversary transistor gets electrical affiliation to 6V AC through baptize and the agnate probe. Which in about-face makes the transistors conduct to afterglow LED and announce the akin of water. The ends of probes are affiliated to agnate credibility in the ambit as apparent in circuit diagram. I
nsulated Aluminum affairs with end insulation removed will do for the probe. Arrange the probes in adjustment on a PVC aqueduct according to the abyss and asperse it in the tank.AC voltage is use to anticipate electrolysis at the probes. So this bureaucracy will endure absolutely long. I agreement at atomic a 2 years of aliment chargeless operation. That’s what I got and is still going.
Part List
nsulated Aluminum affairs with end insulation removed will do for the probe. Arrange the probes in adjustment on a PVC aqueduct according to the abyss and asperse it in the tank.AC voltage is use to anticipate electrolysis at the probes. So this bureaucracy will endure absolutely long. I agreement at atomic a 2 years of aliment chargeless operation. That’s what I got and is still going.
Part List
T1 – T5 BC 548 or 2N2222 Transistors
R1-R5 2.2K 1/4 W Resistors
R6-R10 22K 1/4 W Resistors
D1 – D5 LED’s ( color your choice)
Use a transformer with 6V 500 mA output for power supply. Do not use a rectifier! we need pure AC. Use good quality insulated Aluminum wire for probes. If Aluminum wires are not available try Steel or Tin.Copper is the worst. Try the circuit first on a bread board and if not working properly, make adjustments with the resistance values. This is often needed because conductivity of water changes slightly from place to place. The type number of the transistors used here are not critical and any small signal NPN transistor will do the job. Few other suitable type numbers are BC546, BC107, PN2222, BC337, BF494, ZTX300, BEL187 etc. The circuit can be enclosed in a plastic box with holes for revealing the LEDs .
