Type of charger essential to future large robots (5)
I believe the answer is:
turbo
'type of charger essential to future large robots' is the definition.
I can't tell whether this definition defines the answer.
'type of charger essential to future' is the wordplay.
'type of charger' becomes 'tur' (I am not sure about this - if you are sure you should give a lot more credence to this answer).
'essential to' indicates the central letters.
'future' becomes 'unborn' (I've seen this in another clue).
The middle letters of 'unborn' are 'bo'.
'tur'+'bo'='TURBO'
Can you help me to learn more?
(Other definitions for turbo that I've seen before include "Powerful device" , "Pub torpor (anag) - type of aircraft" , "Type of supercharger using engines exhaust gases" , "found in car" , "source of power" .)