(1) The printed circuit does not allow cross circuits, for the possible cross lines, you can use “drill”, “around” two
two ways to solve. That is, let a lead from another resistor, capacitor, transistor foot gaps “drill” through, or from the possible cross of a lead end.
In special cases where the circuit is complex, it is also allowed to use leads to simplify the design.
In special cases where the circuit is complex, to simplify the design also allows the use of wire jumper, to solve the problem of crossed circuits.
(2) resistors, diodes, tubular capacitors and other components have a “vertical”, “horizontal” two types of installation. Vertical means
is the component body perpendicular to the board installation, welding, the advantage is to save space, horizontal refers to the component body parallel and close to the
The advantage is that the mechanical strength of the component mounting is better. These two different types of mounting components, printed circuit board
Board component hole spacing is not the same.
(3) the same level of circuit grounding point should be as close as possible, and this level of circuit power filter capacitors should also be connected to the level of the grounding point.
location. In particular, the transistor base, emitter grounding point can not be too far away, otherwise the two grounding points between the copper
foil is too long will cause interference and self-excitation, using such a “point grounding method” of the circuit, the work is more stable, not easy to self-excitation.
(4) the total ground must be strictly in accordance with the high-frequency – medium-frequency – low-frequency level in accordance with the weak power to the strong power of the sequential arrangement principle, do not
Do not just flip back and forth, between the level and level rather than wiring longer, but also to comply with this provision. In particular, the frequency head, re
Especially the frequency conversion head, re-generation head, FM head grounding line arrangement requirements are more stringent, such as improper will produce self-excitation so that can not work. FM head, etc.
High-frequency circuits often use a large area around the ground, to ensure that there is a good shielding effect.
(5) strong current leads (common ground, amplifier power leads, etc.) should be as wide as possible to reduce the wiring resistance and its
voltage drop, can reduce the parasitic coupling and self-excitation.