This Telephone bell ringer circuit for generating the electricity bell in the old telephone. R5_39K_0.5 W Resistors tolerance: 5% Telephone bell ringer circuit using IC-KA2411 Q3_2SC1061 or TIP41 or similar_40V 4A NPN Transistorĥ. the electric bell on top layer will loud as well.ġ.
Phone ringer install#
Or can install it on the top layer of the house. The application we select the contact NC-C to control the electric bell. While,we will hear the relay works.Īfter that, Calling your number,then hear the bell ringing and relay-RY1 will stop working. Next,connect both A and B point to the telephone lines. This circuit have a few parts so you can easily build it on the universal PCB. Therefore, the transistors-Q1 get a bias and conduct current, until appear the voltage at the collector lead will be very low, cause both Q2 and Q3 doesn’t conduct current, results not have the current flow to coil of RY1. This signal will through C1 to the diode bridge (D1-D4), the positive rage will through to D1, R3, D4 and R2, but the negative will through to D3, R3, D2 and R2. When it has the incoming call into the telephone lines which is an AC signal about 100 Vp-p. So, the Q2 also conduct current, to apply the coil of relay-RY1 cause it works. While,the voltage at the collector of Q1 will rises, cause the transistor-Q2 get bias and conduct current. Thus, no bias current to the base lead of the transistor-Q1, so it doesn’t conduct current.
In normal state that not have the incoming call, the DC voltage +48 volts will cannot through to the capacitors-C1, so no current flow to D1-D4. This circuit is modified from the speaker protection circuit, so easy and cheap.Īfter that we connect the A and B point to the telephone lines. Then, drive the relay to controls the large electric bells that louder than a general phone. It will increase the signal of the telephone lines up. This is an easy telephone amplifier circuit. RY_Relay 12V normal closed Easy Telephone Amplifiers circuit Figure 2 PCB layout and all components layout of this projects.Ĭ1_0.033uF 600V Polyester CapacitorĬ2_1uF 16V Electrolytic Capacitors
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