Circuit board of the Motorola C123

Circuit board of the Motorola C123  

VHF UHF Low-Noise booster circuit

VHF UHF Low-Noise amplifiers circuit can be designed using the MAX2664 and MAX2665 ultra-compact LNAs for VHF UHF applications.These devices incorporate a broadband LNA with an integrated bypass switch. The MAX2664 covers the UHF frequency range from 470MHz to 860MHz, and the MAX2665 covers the VHF frequency range from 75MHz to 230MHz. Each device has a zero-power bypass mode for improved high-signal-level handling conditions.Both ICs has a high gain around 15dB and require a single power supply , that can provide an output voltage between 2.4 to 3.5 volts .VHF UHF Low-Noise amplifiers has a very low current consumption of 3.3 mA and can be used in applications like : Smartphones/Handsets , MP3 Players , Home Audio/Video and other portable navigation devices .

VHF UHF Low-Noise booster circuit

1.5v to 35v DC Power Supply Circuit.

 

Parts list.
 
IC = LM317
P1 = 4.7K
R1 = 120R
C1 = 100nF - 63V
C2 = 1uF - 35V
C3 = 10uF - 35V
C4 = 2200uF - 35V
D1-D4 = 1N4007

Features:

• Just add a suitable transformer (see table)
• Great to power your projects and save money on batteries
• Suitable as an adjustable power supply for experiments
• Control DC motors, low voltage light bulbs, …

 Specifications :

• Preset any voltage between 1.5 and 35V
• Very low ripple (80dB rejection)
• Short-circuit, thermal and overload protection
• Max input voltage : 28VAC or 40VDC
• Max dissipation : 15W (with heatsink)
• Dimensions : 52x52mm (2.1” x 2.1”)

Technical Specifications

• Input Voltage = 40Vdc max Transformer
• Output Voltage = 1.5V to 35Vdc
• Output Current = 1.5 Amps max.
• Power Dissipation = 15W max (cooled)

Remote Control circuits For Home Appliances

Here is the circuit diagram of Remote Operated Home Appliances or Remote controlled Home appliances. Connect this circuit to any of your home appliances (lamp, fan, radio, etc) to make the appliance turn on/off from a TV, VCD, VCR, Air Conditioner or DVD remote control. The circuit can be activated from up to 10 meters. It is very easy to build and can be assembled on a veroboard or a general-purpose PCB.

Parts:

R1 = 220K
R2 = 330R
R3 = 1K
R4 = 330R
R5 = 47R
C1 = 100uF-16V
C2 = 100nF-63V
C3 = 470uF-16V
D1 = 1N4007
D2 = Red LED
D3 = Green LED
Q1 = BC558
Q2 = BC548
IR = TSOP1738
IC1 = CD4017
RL1 = Relay 5V DC
 

The 38kHz infrared rays generated by the remote control are received by IR receiver module TSOP1738 of the circuit. Pin 1 of TSOP1738 is connected to ground, pin 2 is connected to the power supply through R5 and the output is taken from pin 3. The output signal is amplified by Q1. The amplified signal is fed to clock pin 14 of decade counter IC CD4017 (IC1). Pin 8 of IC1 is grounded, pin 16 is connected to vcc and pin 3 is connected to D2 (Red LED), which glows to indicate that the appliance is ‘off.’

The output of IC1 is taken from its pin 2. D3 connected to pin 2 is used to indicate the ‘on’ state of the appliance. Q2 connected to pin 2 of IC1 drives relay RL1. D1 acts as a freewheeling diode. The appliance to be controlled is connected between the pole of the relay and neutral terminal of mains. It gets connected to live terminal of AC mains via normally opened (N/O) contact when the relay energizes. If you want to operate a DC 12 volt relay then use a regulated DC 12 volt power supply for DC 12 volt Relay and remember that the circuit voltage not be exceeded more than DC 5 volts.

Remote Control circuits For Home Appliances 

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500 Watt Audio Power Amplifier Circuits

What can be done to increase available audio power amplifier? The answer is either decrease load impedance or increase supply voltage. The lower the impedance, the more current is needed, making the construction of low impedance output stages more difficult (there are some other practical limits), so let's increase supply voltage

parts list .

R1,R11
47K
R2,R3 33K
R4 1K5
R5,R7 2K2
R6,R8 100R
R9,R10 56R
R12 820R
R13 10R/5W

C1 220nF
C2,C3,C4 100uF/100V
C5,C6 100pF
C7 100nF/100V

D1,D2 IN4002

TR1,TR2 D438
TR3,TR4 B560
TR5,TR8 A958
TR6,TR7 C2168
TR9,TR10 C2922
TR11,TR12 A1216

Sealed Lead Acid 12V Battery Charger circuits.

There are a cardinal of credibility we allegation to awning about the affliction and use of Sealed Lead Acid batteries.

Firstly, these batteries allegation be charged, absolved and stored actual carefully.

We commonly anticipate batteries can be stored for months (if not years) and they will be accessible for actual use.

This is not the case with SLA batteries.

If you abundance a NEW, abounding answerable SLA array for 6 months or more, you will acquisition it may be absolutely discharged.

You may additionally acquisition you cannot allegation it!! It may be worthless.

That's how aerial SLA batteries are.

They allegation be answerable on a approved base to anticipate them absolution to a actual low voltage level.

If the terminal voltage of a SLA array is accustomed to go beneath 8v, a action alleged SULPHATION starts to awning the apparent of the plates and prevents the array actuality re-charged. The centralized attrition of the array increases and it becomes useless.

 

Parts List.

2 - 1R8 0.5watt resistors

1 - 150R 0.25 watt resistor

1 - 180R

1 - 560R

1 - 1k5

3 - 2k2

1 - 3k3

1 - 4k7

1 - 8k2

1 - 1k mini trim pot

1 - 1n ceramic

2 - 47u 25v electrolytics

1 - 5mm red LED

4 - 1N4148 arresting diodes

1 - 10v 0.25watt zener

1 - BC 547 transistor

2 - BC557 transistors

1 - MCR100-6 SCR

1 - 1m red lead

1 - 1m atramentous lead

2 - alligator clips

1 - 2m actual accomplished solder

1 - SLA Array Charger PCB

Also required:

1 - 12v AC agent (500mA AC)

1 - ability lead

switch mode power supply circuits.

switch mode power supply circuits

Transformerless Power Supply CircuitIf you are not accomplished in ambidextrous with it, again leave this activity alone.Although Mains accessories can itself absorb a lot of current, the circuits we body to ascendancy it, usually alone crave a few milliamps. Yet the low voltage ability accumulation is frequently the better allotment of the...

If you are not accomplished in ambidextrous with it, again leave this activity alone.Although Mains accessories can itself absorb a lot of current, the circuits we body to ascendancy it, usually alone crave a few milliamps. Yet the low voltage ability accumulation is frequently the better allotment of the architecture and a abundant allocation of the cost.

This ambit will accumulation up to about 20ma at 12 volts. It uses capacitive reactance instead of resistance; and it doesn't accomplish actual abundant heat.The ambit draws about 30ma AC. Always use a agglutinate and/or a aqueous resistor to be on the safe side. The ethics accustomed are alone a guide. There should be added than abundant ability accessible for timers, ablaze operated switches, temperature controllers etc, provided that you use an optical isolator as your circuit's achievement device.

MOC 3010/3020) If a broadcast is unavoidable, use one with a mains voltage braid and about-face the braid application the optical isolator.C1 should be of the 'suppressor type'; fabricated to be affiliated anon beyond the admission Mains Supply. They are about covered with the logos of several altered Safety Standards Authorities. If you charge added current, use a beyond amount capacitor; or put two in parallel; but be accurate of what you are accomplishing to the Watts. The low voltage 'AC' is supplied by ZD1 and ZD2.

The arch rectifier can be any of the baby 'Round', 'In-line', or 'DIL' types; or you could use four abstracted diodes. If you appetite to, you can adapt R2 and ZD3 with a 78 Series regulator. The abounding sized ones will work; but if amplitude is tight, there are some baby 100ma versions accessible in TO 92 blazon cases. They attending like a BC 547. It is additionally account acquainted that abounding baby circuits will assignment with an able supply. You can, of course, adapt any or all of the Zenner diodes in adjustment to aftermath a altered achievement voltage. As for the mains voltage, the advancement apropos the 110v adaptation is aloof that, a suggestion. I haven't congenital it, so be able to agreement a little.