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When looking at current passing through a human body, there's a difference between DC current and AC current. One is more dangerous than the other and which one that is, is often a discussion.
This chart tells what current does to a human body (not looking at DC or AC current):
https://www.electricaltechnology.org/wp-content/uploads/2018/07/Current-Range-And-Its-Effects-on-human-body.png
This chart is different per person, the values are an avarage value.
First, we have to know what kind of "electrical parts" the human body haves.
The following diagram is a very simplistic display:
https://www.researchgate.net/publication/307732432/figure/fig1/AS:405963606642688@1473800674071/Equivalent-Electrical-circuit-model-of-the-human-body-5.png
In the diagram, Ri and Cin are a RC circuit.
The human body consists of many small dielectric parts which all act like a capacitor.
Ro is a varistor, which means its resistance will decrease when the voltage increases.
Ro is wired parallel to Ri and Cin.
Ri and Ro will act the same on DC and AC voltage (minding the varistor function of Ro), but Cin will not.
Capacitors will "block" when they are connected on DC currents and will conduct when connected to AC currents.
This means, when the circuit is connected to DC supply, only a current will flow through Ro. However, when it's connected to AC supply, current will flow through Ro, Ri and Cin creating a parallel circuit of resistors, which creates a equivalent resistance.
This is calculated by next formulas:
REQ = (Ro × Ri) ÷ (Ro + Ri) or
1 ÷ REQ = (1 ÷ Ro) + (1÷ Ri).
This means the equivalent resistance is always lower than the lowest resistor in the circuit.
In the end, this means AC currents are more dangerous than DC currents. Also due to the frequency we use, 50 or 60 Hz. This is a dangerous frequency for the heart.
Yes, when grabbing a live wire with DC current, it is harder to let go of than with AC current. But, 50 or 60 Hz AC current is also very hard to let go of because the voltage changes polarity 100 or 120 times a second which can be too fast for muscles to relax enough to let go of the conductor.
With AC current a 3rd factor comes in. When we say "110 VAC" or "230 VAC" we mean the effective voltage (Urms). The AC rms voltage is equal to the value of a DC current that would produce the same power dissipation in a resistive load. When looking at peak AC voltage (Up) the Urms needs to be multiplied by √2 (1.414).
This means that, when looking at 110 VAC and 230 VAC rms, the peak voltages would be ± 156 VAC and 325 VAC.
This means a higher voltage (Up instead of Urms) will be present on the conductor.
In the simulated circuit on the top left, 3 DC and 3 AC supplies are situated. 1 DC and 1 AC supply are connected with a C.O. switch as a group. With this switch DC current or AC current can be chosen. Each group of DC and AC supply haves the same effective voltage (Urms). The 1st group: 50 VDC and 50 VAC rms. The 2nd group: 110 VDC and 110 VAC rms. The 3rd group: 230 VDC and 230 VAC rms.
50 VAC rms and 110 VDC are considered the max. safe voltages.
With the N.O. switches (1 per group) the chosen DC or AC current can be supplied to the circuit.
Only 1 N.O. switch can be active!!
In the circuit, resistors are placed on the left and a RC circuit is placed on the right. Note that, on the 3 left resistors, the left resistor haves a higher Ω value than the right resistor. This simulates the varistor part of the human body.
The relay coils will also behave different to the supplied voltages. The higher the supplied voltage, the more relays will be active. This also simulates the varistor part of the body (equivalent risistance).
Play around with the voltages and watch how the current runs through the circuit.
The Ω and F values are not taken from real life or proven documents. I've chosen them to my best feeling when looking at the chart of current values and my own experience with electricity.
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