I want to buy a water pump that has capacity DC 3.5V-9V 3W which by my 5V USB charger makes 0.6A. My charger has output 5W 1A. Is it safe to exceed the 0.6A value by 0.4A?
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JRE
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Marcel Kopera
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1The pump will only draw the amount of current it needs, the power supply does not force more current trough the load then it requires. A pump might draw a current spike at start-up tough. – Unimportant Jul 26 '21 at 11:55
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It’s never wise to exceed rated current with surges without storage capacity depending inrush current limits.
The pump power may rise >500% on startup and drop to 5/9 th of 3W max at 5V depending on load or lower. It is unknown how your load will react unless you test it with a flyback protection diode to opposite power rail.
Measuring pump DCR will tell you the start resistance and surge current.
Tony Stewart EE75
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thanks for the answer! So if I understand it good, it will takes only the current it needs, but it can instantly go high on a start so it could broke? – Marcel Kopera Jul 26 '21 at 12:00
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