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Mini FM Transmitter using MAX2606

With MAX2606 you can make a Mini mono FM transmitter. It is built with MAX2606 and covers at least 20 meters with 1.5 m length of copper wire antenna. You can use this transmitter as an oscillator, but change the 1000pF capacitor of the antenna with 15pF.

MAX2606 transmitter output power is-10dBm, which means something around 100uW (micro-watts) = 0.0001. Of course this is very low, so it is recommended the use of auxiliary power amplifier, if you want to build a more powerful transmitter based on MAX2606. You can find a power amplifier in a few fm electroschematics.com so please use the search box.

BA5417 Stereo Power Amplifier

Setup and dealing of this stereo power amplifier circuit is somewhat similar to the BA5406 based mostly stereo amplifier circuit revealed previously. C10 and C11 are DC decoupling capacitors that block any DC level present in the input signals. C2 and C6 couples the amplifiers left and right power outputs to the corresponding loud speakers. C1 and C5 are bootstrap capacitors.

Bootstrapping is a technique during which a portion of the amplifiers is taken and applied to the input. The prime objective of bootstrapping is to boost the input impedance. Networks R1,C3 and R2,C7 are meant for improving the high frequency stability of the circuit. C4 is the power supply filter capacitor. S1 is the standby switch. C8 is a filter capacitor. R3 and R4 sets the gain of the left and right channels of the amplifier in conjunction with the 39K internal feedback resistors.

LM1758 A Switching Regulator Circuit

The National Semiconductor LM 1578 A is a switching regulator which can simply be created for such dc-to-dc voltage, conversion circuits as the buck, boost, and inverting configurations. The LM 1578 A features a unique comparator input stage that not only has separate pins for each the inverting and non-inverting inputs, however also provides an internal 1.0 V reference to every input, thereby simplifying circuit design and pc board layout.

The output can switch upto 750 m A and has output pins for its collector and emitter to promote design flexibility. An external current limit terminal is also referenced to either the ground or the Vin terminal, relying upon the application. additionally, the LM 1578 A has an on board oscillator, that sets the switching frequency with one external capacitor from < 1 Hz to 100 kHz (typical). It operates from supply voltages of 2 V to 40 V. it's supplied with current limit and thermal shutdown. Duty cycle up to 90 %. functional diagram is given in figure.

5 Channel Radio Remote Control

This article is about an easy 5 channel radio remote control circuit based on ICs TX-2B and RX-2B from Silan Semiconductors. TX-2B / RX-2B is a remote encoder decoder combine that can be employed for remote control applications. TX-2B / RX-2B has five channels, wide operating voltage range (from 1.5V to 5V), low stand by current (around 10uA), low operating current (2mA), auto power off function and needs few external parts. The TX-2B / RX-2B was originally designed for remote toy car applications, however it can be used for any kind of remote switching application.

3 Channel LED Driver using CAT3063

The circuit diagram of a three channel LED driver circuit using CAT3063 is apparent here. C4 is an ascribe clarify capacitor. R1 is the resistor acclimated for programming the achievement current. C3 is the achievement clarify capacitor. C1 and C2 are the accumulator capacitors of the centralized allegation pump circuit. A argumentation top at pin 5 will accredit the IC and a argumentation low on the aforementioned pin will drive the IC into abeyance mode. In the abeyance mode, the quiescent accepted is about according to zero. With the acclimated amount of R1, the LED accepted per approach will be 25mA.

When powered up the CAT6063 operates in 1X approach i.e, the achievement voltage will be according to the ascribe voltage. If this achievement voltage is abundant to adapt the accepted through all LEDs, the IC charcoal 1X mode. If the achievement voltage is not acceptable abundant to adapt the adapted accepted through the LEDs, the accessory automatically switches to the 1.5X approach area the achievement voltage is 1.5 times the ascribe voltage. This action is again if anytime the IC is powered up or activate from abeyance mode.