LB1948M bassed forward reverse motor control driver circuit with explanation

A very simple forward reverse motor control driver electronic circuit project can be designed using the LB1948M 2 channel low saturation voltage forward reverse motor control driver IC. LB1948M motor driver is optimal for motor drive in 12V system products and can drive either two DC motors, one DC motor using parallel connection, or a 2-phase bipolar stepping motor with 1-2 phase excitation mode drive.
Some features of the LB1948M motor driver IC are : 12V power supply ,low saturation voltage: VO(sat) = 0.5V (typical) at IO = 400mA ,zero current drawn in standby mode , braking function ,built-in thermal shutdown circuit .

The LB1948M can be used as a single-channel H-bridge power supply by connecting IN1 to IN3, IN2 to IN4, OUT1 to OUT3, and OUT2 to OUT4 as shown in the figure. (IOmax=1.6A, VO(sat)=0.6V (typical) at IO=800mA) .
The circuit is very simple and require few external electronic parts .

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Audio line driver

Audio line driver

Description.

This is the circuit diagram of a two channel audio line driver using the high performance dual opamp IC TSH22 from ST Microelectronics. The 25 MHz bandwidth, low distortion and high output current of the IC makes it possible to drive medium impedance loads at a high level of modulation.

Here both of the opamps inside the IC are wired as non inverting amplifiers with 3X gain, one for each channel. Input line 1 is connected to the non inverting input of IC1a and input line 2 is connected to the non inverting input of IC1b. The non inverting inputs of the opamps IC1a and IC1b are pulled to a slight positive voltage using the R1 and R9 respectively. The resistance R4 and R2 are used to make a phantom ground at half the supply voltage.


Notes.
Assemble the circuit on a good quality PCB.
The circuit can be powered from 12V DC.
At 12V supply, a 600 ohm impedance line can be driven at +10dBm with a distortion less than 0.05% at 1kHz.
Gain of line 1 can be set using the equation, Gain1 = (R5+R6)/R6.
Gain of line 2 can be set using the equation, Gain2 = (R7+R8)/R8.
The load at the output must be at least 100 ohms in order to avoid stability issues.

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Constant Current LED Driver Circuit

 If an LED is used in a circuit, the current for that LED is normally set with a limiting resistor. The LED can then be switched on and off by means of a transistor.
The following discussions explains a transistor based configuration which ensures a constant current drive to the conected LEDs, under  all circumstance.

However, the method shown in figure l does not take into account any variations in the supply voltage. A small variation in the LED current can be very conspicuous especially when high efficiency LEDs are used. The addition of just one transistor can transform the circuit of figure 1 to a onstant current source which can be switched on an off (for instance, with TTL levels). The circuit of figure 2 shows that resistor R1 has been moved to the emitter of T1. When a drive voltage is applied to the input of T1, this transistor conducts which causes a current through R1. Transistor T2 controls the base current of T1 such that I the voltage drop across R1 remains at 0.6 V. The current, l, through the LEDs and R1 is calculated by l= 0.6/R1. lf, for instance, R1 is 12 S2, the current through the LEDs is 50 mA. Bear in mind that the dissipation of T1 is somewhat higher than in the circuit of figure 1, but against that, the dissipation in R1 is not as high.

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Loudspeaker Driver Circuit

The series of loudspeaker drivers are electronic circuits that function to bridge between high-output circuit with a loudspeaker berimpedasi berimpedansi low. 

Why this driver is needed so that the output voltage to be inserted into the loudspeaker is not impaired. Declining value of this voltage is very possible given the lack of rules regarding the distribution of voltage and resistance instead of parallel. Where every prisoner that is placed parallel with other prisoners or the inmates totally substitute for detainee custody is smaller than with individual prisoners themselves. For example, 10 ohm resistance 10 ohms paralleled with the prisoners would get custody instead of 5 ohms. Resistivity 10 ohm to 100,000 ohm paralleled the total resistance is 9.9990 ohms. So it can be concluded that the total voltage will always be smaller than the origin of each detainee. Then, with a decrease in resistance (only using a combination of resistors) or the impedance of the output terminals before, then in accordance with the laws of the voltage divider in series can be ascertained that the prisoners connect in series with output terminal will have a larger part of the voltage and output terminal itself will decline voltage.

The working principle speaker driver circuit is actually very simple and easy to understand. Where the input signal is only used as a trigger to move the second driver transistor to the rhythm of the input signal. While the current that would flow to the loudspeaker most of the power supply driver circuit. You could say similar to the use of transistors as switches. Therefore, in this speaker series driver not found a combination of resistors for reinforcement. So if we look at the picture above, so most of the current flowing in the loudspeaker load is derived from the 9 volt supply voltage, instead of the input ac signal, so that the input signal will not be burdened.

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