Federal Reserve Bank of Dallas President Richard Fisher said adequate economic stimulus is in place and that global central banks may not have the capacity to undertake additional measures.

“We’re at the risk of overburdening the central banks,” Fisher said in an interview on “Bloomberg Surveillance” with Tom Keene.

“We keep applying what I call monetary Ritalin to the system. We all know there’s a risk of overprescribing.” (Ritalin is a drug used to treat depression and hyperactivity in children.)

Editor's Note: Economist Unapologetically Calls Out Bernanke, Obama for Mishandling Economy. See What They Did

Fed Chairman Ben Bernanke said July 17 that policy makers were studying options for further stimulus. The Fed refrained from announcing steps at a meeting last week.

Meanwhile, Fisher said the largest banks have $1.5 trillion in excess reserves that they would like to put to work and that the private sector now must take the next steps to boost growth. Lawmakers also must act to eliminate uncertainty about government spending and tax rates, Fisher said.

“We have done our job,” Fisher said of the Fed. “We have done enough. Just doing more doesn’t solve the problem. The problem is engaging the transmission. We provided the gas, the gas tank is full.”

The Dallas Fed chief isn’t a voting member of the policy-making Federal Open Market Committee this year. He dissented last year twice against moves to push down long-term rates and to keep the benchmark U.S. interest rate near zero until at least mid-2013. He voted five times in 2008 in favor of tighter policy.

"Whether you are a hawk or a dove, whether you are the heard of the Federal Reserve Bank of Boston or Dallas or one of the Federal Reserve governors, all of us are trying to figure out how to deliver on our mandate," he said.

"We have a mandate from Congress to conduct monetary policy so as to keep price stability. All of us believe, including hawks like me, that the immediate threat to the system is not inflation," he said.

"The other issue is how do we fulfill the mandate to create the conditions to achieve full employment? That is where you have a difference of view and a discussion taking place. I should remind you it is a civil discussion, not like Congress, where we beat each other to a pulp. We’re working very hard to get the right answer.”

Editor's Note: Economist Unapologetically Calls Out Bernanke, Obama for Mishandling Economy. See What They Did