Shunt current regulator for downhole devices

A method of current regulation, the method comprising:

• monitoring, by a sensing element, a current drawn from a tubing encapsulated cable extending downhole from a surface through a wellbore;
• generating a sense signal from the sensing element;
• generating a compensation signal from the sense signal;
• and
• controlling a transistor to regulate the current drawn from the tubing encapsulated cable extending downhole, wherein the controlling comprises:
• dissipating power in the transistor to stabilize the current drawn;
• and
• providing compensation current to increase the current drawn.

A system comprising:

• a processing device couplable to a tubing encapsulated cable extending downhole from a surface through a wellbore, wherein the processing device is operable to:
• decode communication from a downhole node;
• and
• send communication to the downhole node;
• the downhole node comprising:
• a switch mode voltage regulator couplable to the tubing encapsulated cable;
• a shunt current regulator to maintain a stable cable current couplable to the switch mode voltage regulator, the shunt current regulator including a sensing element to monitor a current drawn from the tubing encapsulated cable extending downhole;
• and
• a current load.