Electronic energy-saving lamp circuit (1)

The electronic energy-saving lamp introduced in this example uses a low-power low-voltage tungsten lamp as the lighting source. Since
the volume of the tungsten-halogen bulb is only 1/50 of the ordinary white-out bulb with the same power, the light intensity and life span are 2~ of the latter. 3 times, so
under the same illumination conditions, using tungsten halogen lamps has obvious energy saving effect. The circuit is shown in Figure 287. This circuit is very suitable
for use as a desk lamp.
    After the Atai power switch S1 is turned on, the 220V AC power is rectified by VD! - VD4 and outputs
a DC voltage of about 300v. Brother, VTH, & and G form a trigger circuit to provide trigger voltage for VT2. VT1 and VT2
form an electronic switch tube, and VT1 and VT2 are used for time and space switching and cutoff. VT1,L. ,R,,VT2,J,:,R. ,superior. ,
L s, c and (: Shao Cheng white excitation oscillation circuit, the oscillation frequency is '/OkHz-30 kl-h. L, (,,, (1, ′ =
operating in series oscillation state - oscillation voltage through T2 Coupled to L. Powers the tungsten halogen bulb E. sz is the brightness selection
switch. The position shown in the picture is
the island bright state. For example, if
s2 is moved to the position ①¨ inch,
it is the sunny state -
VD5, R, VDH,
R . 5Vn7 is
a protective component, which can eliminate the impact of the reverse peak lU voltage generated by the
oscillation coil
on VT1 and
VT2.
    VT1 and wr2
iiJ use MTE13003-13005 WJ high-power tubes with a p value of 20-10, requiring the characteristics of the two tubes In particular, the port
values ​​are required to be as consistent as possible. Tl and T2 need to be made in white: the three coils of Tl can be wound with ≠0.4mm
single-strand copper wire of different colors and a high-frequency magnetic ring r-winding with an outer diameter ≠10mm, L ., L: Double wire and wind 6 5 turns.,,. Wind 2
turns. When assembling, pay attention to the end of the coil with the same name. T2 uses E1 type ferrite core with a cross-sectional area of ​​iOmmX
7mm.』; and L, use For example , when winding 27mm high-strength polyester enameled wire, wind it first, it will be 122 claws, pull out one end
and then wind 25 rt to L... Add an insulating
layer. F adopts 33jW, 12V low-voltage halogen tungsten bulb. Other component parameters are shown in the figure.
    This circuit generally does not need to be tested, and it can work normally when it is powered on. If the circuit cannot oscillate, it is usually the same terminal of the coil.
Wrong. When the circuit is operated for a long time, VT1, VT2 and T2 should all be obviously warm. If the T2
core is hot, adjust the core air gap to solve the problem. If the core is normal, replace the core.