(b) Multi-point ground scheme
- In case of Multi-point ground scheme, all equipments are connected to solid ground conducting plane which is earthed for safety reason.
- In this case individual grounds are connected to single large ground. In using a multi point ground system it is assumed that the ground returns to which the individual grounds are terminated has a very low impedance between any two points at the frequency of interest.
- Otherwise, there would be no technical distinction between this and the series connection, single point ground system.
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| Multi Point Ground Scheme |
- Practically it is seen that ground size is high as compared to operating wavelength when operating frequencies are high. Thus at high frequencies, Multi-point ground behaves perfect conductor and results in zero potential at different Interconnected points by ground. Multi-point ground scheme is shown in Fig.
Advantages of Multi-Point Ground Scheme
- Connection length can be shorter as nearby ground reference plane is available.
- It is simple to implement.
Limitations of Multi-Point Ground Scheme
- During implementation of Multi-point ground scheme, simply connecting individual ground to reference ground won't work, but designer has to check whether zero impedance at the point of connection at operating frequency.
- Care related to amplitude of current through reference ground must be taken while connecting low and high current circuits.
(c) Hybrid Grounding Scheme
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| Hybrid Grounding Scheme |
- In this scheme, at low frequencies ground current loop Is avoided by capacitor at one ground. Whereas at high frequencies, capacitor produces low reactant and it connected equipment gets grounded.
- Thus scheme simultaneously work as single and multi-point grounding scheme and thus famous as Hybrid-Ground Scheme.
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