Recently, widespread quartz alarm clock made in China, characterized by a relatively high ring volume and cheapness. If the watch is out of order, but the alarm clock still works, it can be used in a variety of makeshift structures. For example, the proposed indicator of a bite.
Performance capabilities of such a device to fully appreciate the avid fishing enthusiasts (especially night). Make sure: the reaction of the same reliable electronics as a sharp bite, and careful as to poticu inside of the reservoir, and the movement toward the shore, and the signal is light and sound.
Based on the work of the indicator — the interaction of the magnetically operated contacts (reed switch) with a permanent magnet While the magnet is near the reed switch, the contacts are in the same condition as when you remove the magnet in the other.
When the contacts of the reed switch SF1 turns off (and this is the situation when carrying this unit), transistors VT1, VT2 are closed (Fig. 1). Hence, the energy consumption will be minimal. Indeed, when using the alarm device paired with the standard 1,5 volt galvanic element supply current less than 1 µa.
In standby mode, when the magnet almost touching the contacts of the reed switch, they are closed, but the status indicator does not change.
Fig. 1. Circuit diagram (a) of the bite indicator is based on the real-time clock Wake-up Chinese production and the symbol of the conclusions from the Board (b)
However, it should at least short-term magnet to move relative to the axis of the reed switch forward or backward as the contacts of the reed switch will immediately open. At the base of the first transistor through a chain R1С1 will go negative pulse. VT1 opens, and through it will charge the capacitor C2. However, this, in turn, will unlock the second transistor and turn on the sound generator of an alarm clock. The capacitor C2 begins to discharge through resistor R3 and the emitter transition of transistor VT2.
The duration of the generator depends on the parameters of the chain С2RЗ and specified in the diagram the values of approximately 2 s. during this time and will beep.
variable voltage output 3 alarm is supplied via a capacitor C3 to the diode НL1 and he erupts. The brightness depends on the denomination of C3. Unfortunately, it is small, because increasing the capacity of this capacitor, the volume of the alarm sound will decrease.
Fig. 2. Schematic amplifier circuit for increasing the brightness of the light indicator bite
Fig. 3. Rod is equipped with an electronic bite alarm:
1 — beach; 2 — alarm bite; 3 — rod; 4 — the magnet on the fishing line; 5 — pond
The reed switch can be CAM-1, CAM-2 or the like, with contacts operating in the circuit. Transistors — any of a number of widespread low-power semiconductor devices (just the type and polarity of inclusion observed). The quality of the capacitors is the best fit KM-6 and bolsheselsky K50-35 (C3 in Fig. 2). Resistors — MLT-0,125 or MLT-0,25. Diode any silicon; led, from АЛ307.
The magnet can be borrowed from the security alarm sensor SMK in a plastic housing with holes for fastening the fishing line. It is possible to use and more accessible: for example, from the furniture latches. To the permanent magnet with epoxy glue EAF attach two rings at such a distance that after getting on the line, he could not be rotated around its axis.
Mounted a circuit diagram of the device is placed in a housing made of plastic boxes (Fig. 3). The led is fixed to the lid with glue or epoxy 88Н. Opposite the emitter of the alarm clock in the side wall of the cover hole is drilled, and on top of the lid draw a rectangle around the reed switch — it will allow you to Orient the permanent magnet.
While fishing, a fishing rod, warning device and a permanent magnet placed as shown in figure 3.
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