BC337 | Electronic Project Circuits

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Step down voltage converter 5v with transistor BC337

The circuit decreases the size voltage or Stepdown Voltage converter circuit be dc regulated circuit model switching converter. The that make voltage output there is the size voltage a little more input at feed give with the circuit. From circuit picture will decrease volt 6-18V from be left 5V. It give current get 100mA.

When feed volt give with transistor circuit Q1 and Q2 the connection is astable multi vibrator. Will do frequency production comes out at a collector pin of Q2 and transmit come to at a B pin of Q3. By Q3 perform like with switch wait for close-open the circuit for control to give Q4 work. When base pin of Q4 have voltage bias make Q4 work. The C3 perform charge by change the way coil L1 make output have voltage increase continually. But if be valuable 5V more than bear fruit make Q5 work. Because have voltage come to bias at B pin by change the way ZD1 switch off work because of volt at a B pin of Q1 be 0V. The circuit then stop to produce the frequency comes out. Then make Q4 stop work with. When Q4 stop work then have no Vbias give Q5 then stop work thus Q1 then can work again and work character repeated as like this before. But there are many speeds then make output that appear can come out 5V all the time.

Be the first to comment - What do you think? Posted by admin - May 26, 2010 at 10:11 pm

Categories: Switching power supply Tags: BC337, step down regulator, switching power supply 5V

Capacitive Sensor(Touch switch relay) with BC337

Special design for shop-windows animation
Useful for many types of touch controls

The purpose of this circuit is to animate shop-windows by means of a capacitive sensor placed behind a post-card-like banner. The card is placed against the glass inside the shop-window, and the visitor can activate the relay placing his hand on the card, from the outside. Especially suited for toy-shops, the circuit can activate model trains, small electric racing cars, lights etc. Further applications are left at user’s imagination. Adopt it to increase the impact of your shop-window on next Christmas season!

Parts:
R1,R2_____1M 1/4W Resistors
R3,R4____47K 1/4W Resistors
C1_______10µF 25V Electrolytic Capacitor
C2______470pF 630V Ceramic or Polyester Capacitor
D1-D3____1N4002 100V 1A Diodes
Q1-Q3_____BC337 45V 800mA NPN Transistors
RL1_______Relay with SPDT 2A @ 220V switch
Coil Voltage 12V. Coil resistance 200-300 Ohm
J1________Two ways output socket
Sensor____Aluminium or copper thin sheet with the dimensions of a post-card,
glued at the rear of the same (about 15×10.5 cm.)
Thin screened cable

Please read more at the original source: http://www.redcircuits.com//Page22.htm
Thank you.

Be the first to comment - What do you think? Posted by admin - September 14, 2007 at 9:07 pm

Categories: Electronic Control Tags: BC337, circuit switches, touch sensitive switch, touch-relay-switch

One-IC two-tones Siren with IC 4093

Double-tone Police sound Single-tone old ambulance sound

This circuit is intended for children fun, and can be installed on bicycles, battery powered cars and motorcycles, but also on models and various games and toys. With SW1 positioned as shown in the circuit diagram, the typical dual-tone sound of Police or Fire-brigade cars is generated, by the oscillation of IC1A and IC1B gates. With SW1 set to the other position, the old siren sound increasing in frequency and then slowly decreasing is reproduced, by pushing on P1 that starts oscillation in IC1C and IC1D.
The loudspeaker, driven by Q1, should be of reasonable dimensions and well encased, in order to obtain a more realistic and louder output. Tone and period of the sound oscillations can be varied by changing the values of C1, C2, C5, C6 and/or associated resistors. No power switch is required: leave SW1 in the low position (old-type siren) and the circuit consumption will be negligible.

Parts:
R1,R3___470K 1/4W Resistors
R2______680K 1/4W Resistor
R4_______82K 1/4W Resistor
R5______330K 1/4W Resistor
R6_______10K 1/4W Resistor
R7_______33K 1/4W Resistor
R8________3M3 1/4W Resistor
C1,C5_____10µF 25V Electrolytic Capacitors
C2,C6_____10nF 63V Polyester Capacitors
C3_______100nF 63V Polyester Capacitor
C4_______100µF 25V Electrolytic Capacitor
D1-D3___1N4148 75V 150mA Diodes
IC1_____4093 Quad 2 input Schmitt NAND Gate IC
Q1______BC337 45V 800mA NPN Transistor
P1______SPST Pushbutton
SW1_____DPDT Switch
SPKR____8 Ohm Loudspeaker
B1______6V Battery (4 AA 1.5V Cells in series)